专栏首页ccf19881030的博客VS2017中使用CppSQLite报出编译器错误C2440

VS2017中使用CppSQLite报出编译器错误C2440

最近在VS2017中使用CodeProject上面的CppSqlite这个Sqlite的C++封装库时,引入了sqlite.lib以及CppSqlite的两个文件CppSQLite3.h和CppSQLite3.cpp,其地址为:CppSQLite - C++ Wrapper for SQLite,报错如下:

1>------ 已启动生成: 项目: FtpUploadMulti, 配置: Debug Win32 ------
1>CppSQLite3.cpp
1>f:\rate\workspace\include\cppsqlite3.cpp(203): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(205): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(237): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(239): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(270): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(272): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(372): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(374): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(474): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(476): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(521): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(523): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(533): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(535): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(548): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(550): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(563): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(565): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(625): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(627): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(724): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(726): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(750): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(752): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(854): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(856): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(869): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(871): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(882): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(884): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1001): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1003): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1015): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1017): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1029): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1031): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1044): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1046): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1058): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1060): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1071): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1073): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1167): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1169): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1178): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1180): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1280): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1282): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1360): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1362): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>f:\rate\workspace\include\cppsqlite3.cpp(1409): error C2440: “<function-style-cast>”: 无法从“initializer list”转换为“CppSQLite3Exception”
1>f:\rate\workspace\include\cppsqlite3.cpp(1411): note: 无构造函数可以接受源类型,或构造函数重载决策不明确
1>已完成生成项目“FtpUploadMulti.vcxproj”的操作 - 失败。
========== 生成: 成功 0 个,失败 1 个,最新 0 个,跳过 0 个 ==========

可以看出CppSQLite3Exception这个类的构造函数报出了C2440错误,关于编译器错误 C2440,微软官网给出了一些示例,地址为:编译器错误 C2440 查看报错的地方结合微软官网编译器错误 C2440 从下面微软官方给出的示例中可以看出问题所在:

我们可以看到CppSQLite3.h中关于CppSQLite3Exception类有两个构造函数,其中一个函数原型为:

    CppSQLite3Exception(const int nErrCode,
                    char* szErrMess,
                    bool bDeleteMsg=true);

报错的调用函数为:

if (nField < 0 || nField > mnCols-1)
   {
   	throw CppSQLite3Exception(CPPSQLITE_ERROR,
   							"Invalid field index requested",
   							DONT_DELETE_MSG);
   }

类似于这种,可以看出,C++将字符串常量"Invalid field index requested" 即const char []数组类型转换成char报错了。 1>f:\rate\workspace\include\cppsqlite3.cpp(474): error C2440: “”: 无法从“initializer list”转换为“CppSQLite3Exception” 1>f:\rate\workspace\include\cppsqlite3.cpp(476): note: 无构造函数可以接受源类型,或构造函数重载决策不明确 由于CppSQLite3.cpp这个文件中有好多处使用了 CppSQLite3Exception(const int nErrCode,char szErrMess,bool bDeleteMsg=true);这个函数,所以比较好的解决办法是将这个构造函数的原型稍作修改,将第二个参数从char改成const char,即改成如下方式:

 CppSQLite3Exception(const int nErrCode,
                    const char* szErrMess,
                    bool bDeleteMsg=true);

这样错误就解决了。

CppSqlite的头文件和源文件

最后附上修改后的CppSQLite3.h和CppSQLite3.cpp文件的源代码:

  • CppSQLite3.h
// CppSQLite3 - A C++ wrapper around the SQLite3 embedded database library.
//
// Copyright (c) 2004..2007 Rob Groves. All Rights Reserved. rob.groves@btinternet.com
// 
// Permission to use, copy, modify, and distribute this software and its
// documentation for any purpose, without fee, and without a written
// agreement, is hereby granted, provided that the above copyright notice, 
// this paragraph and the following two paragraphs appear in all copies, 
// modifications, and distributions.
//
// IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
// INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST
// PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION,
// EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF
// ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". THE AUTHOR HAS NO OBLIGATION
// TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
//
// V3.0		03/08/2004	-Initial Version for sqlite3
//
// V3.1		16/09/2004	-Implemented getXXXXField using sqlite3 functions
//						-Added CppSQLiteDB3::tableExists()
//
// V3.2		01/07/2005	-Fixed execScalar to handle a NULL result
//			12/07/2007	-Added int64 functions to CppSQLite3Query
//						-Throw exception from CppSQLite3DB::close() if error
//						-Trap above exception in CppSQLite3DB::~CppSQLite3DB()
//						-Fix to CppSQLite3DB::compile() as provided by Dave Rollins.
//						-sqlite3_prepare replaced with sqlite3_prepare_v2
//						-Added Name based parameter binding to CppSQLite3Statement.

#include "CppSQLite3.h"
#include <cstdlib>


// Named constant for passing to CppSQLite3Exception when passing it a string
// that cannot be deleted.
static const bool DONT_DELETE_MSG=false;


// Prototypes for SQLite functions not included in SQLite DLL, but copied below
// from SQLite encode.c

int sqlite3_encode_binary(const unsigned char *in, int n, unsigned char *out);
int sqlite3_decode_binary(const unsigned char *in, unsigned char *out);





CppSQLite3Exception::CppSQLite3Exception(const int nErrCode,
									const char* szErrMess,
									bool bDeleteMsg/*=true*/) :
									mnErrCode(nErrCode)
{
	mpszErrMess = sqlite3_mprintf("%s[%d]: %s",
								errorCodeAsString(nErrCode),
								nErrCode,
								szErrMess ? szErrMess : "");

	if (bDeleteMsg && szErrMess)
	{
		sqlite3_free((void*)szErrMess);
	}
}

									
CppSQLite3Exception::CppSQLite3Exception(const CppSQLite3Exception&  e) :
									mnErrCode(e.mnErrCode)
{
	mpszErrMess = 0;
	if (e.mpszErrMess)
	{
		mpszErrMess = sqlite3_mprintf("%s", e.mpszErrMess);
	}
}


const char* CppSQLite3Exception::errorCodeAsString(int nErrCode)
{
	switch (nErrCode)
	{
		case SQLITE_OK          : return "SQLITE_OK";
		case SQLITE_ERROR       : return "SQLITE_ERROR";
		case SQLITE_INTERNAL    : return "SQLITE_INTERNAL";
		case SQLITE_PERM        : return "SQLITE_PERM";
		case SQLITE_ABORT       : return "SQLITE_ABORT";
		case SQLITE_BUSY        : return "SQLITE_BUSY";
		case SQLITE_LOCKED      : return "SQLITE_LOCKED";
		case SQLITE_NOMEM       : return "SQLITE_NOMEM";
		case SQLITE_READONLY    : return "SQLITE_READONLY";
		case SQLITE_INTERRUPT   : return "SQLITE_INTERRUPT";
		case SQLITE_IOERR       : return "SQLITE_IOERR";
		case SQLITE_CORRUPT     : return "SQLITE_CORRUPT";
		case SQLITE_NOTFOUND    : return "SQLITE_NOTFOUND";
		case SQLITE_FULL        : return "SQLITE_FULL";
		case SQLITE_CANTOPEN    : return "SQLITE_CANTOPEN";
		case SQLITE_PROTOCOL    : return "SQLITE_PROTOCOL";
		case SQLITE_EMPTY       : return "SQLITE_EMPTY";
		case SQLITE_SCHEMA      : return "SQLITE_SCHEMA";
		case SQLITE_TOOBIG      : return "SQLITE_TOOBIG";
		case SQLITE_CONSTRAINT  : return "SQLITE_CONSTRAINT";
		case SQLITE_MISMATCH    : return "SQLITE_MISMATCH";
		case SQLITE_MISUSE      : return "SQLITE_MISUSE";
		case SQLITE_NOLFS       : return "SQLITE_NOLFS";
		case SQLITE_AUTH        : return "SQLITE_AUTH";
		case SQLITE_FORMAT      : return "SQLITE_FORMAT";
		case SQLITE_RANGE       : return "SQLITE_RANGE";
		case SQLITE_ROW         : return "SQLITE_ROW";
		case SQLITE_DONE        : return "SQLITE_DONE";
		case CPPSQLITE_ERROR    : return "CPPSQLITE_ERROR";
		default: return "UNKNOWN_ERROR";
	}
}


CppSQLite3Exception::~CppSQLite3Exception()
{
	if (mpszErrMess)
	{
		sqlite3_free(mpszErrMess);
		mpszErrMess = 0;
	}
}




CppSQLite3Buffer::CppSQLite3Buffer()
{
	mpBuf = 0;
}


CppSQLite3Buffer::~CppSQLite3Buffer()
{
	clear();
}


void CppSQLite3Buffer::clear()
{
	if (mpBuf)
	{
		sqlite3_free(mpBuf);
		mpBuf = 0;
	}

}


const char* CppSQLite3Buffer::format(const char* szFormat, ...)
{
	clear();
	va_list va;
	va_start(va, szFormat);
	mpBuf = sqlite3_vmprintf(szFormat, va);
	va_end(va);
	return mpBuf;
}




CppSQLite3Binary::CppSQLite3Binary() :
						mpBuf(0),
						mnBinaryLen(0),
						mnBufferLen(0),
						mnEncodedLen(0),
						mbEncoded(false)
{
}


CppSQLite3Binary::~CppSQLite3Binary()
{
	clear();
}


void CppSQLite3Binary::setBinary(const unsigned char* pBuf, int nLen)
{
	mpBuf = allocBuffer(nLen);
	memcpy(mpBuf, pBuf, nLen);
}


void CppSQLite3Binary::setEncoded(const unsigned char* pBuf)
{
	clear();

	mnEncodedLen = strlen((const char*)pBuf);
	mnBufferLen = mnEncodedLen + 1; // Allow for NULL terminator

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	memcpy(mpBuf, pBuf, mnBufferLen);
	mbEncoded = true;
}


const unsigned char* CppSQLite3Binary::getEncoded()
{
	if (!mbEncoded)
	{
		unsigned char* ptmp = (unsigned char*)malloc(mnBinaryLen);
		memcpy(ptmp, mpBuf, mnBinaryLen);
		mnEncodedLen = sqlite3_encode_binary(ptmp, mnBinaryLen, mpBuf);
		free(ptmp);
		mbEncoded = true;
	}

	return mpBuf;
}


const unsigned char* CppSQLite3Binary::getBinary()
{
	if (mbEncoded)
	{
		// in/out buffers can be the same
		mnBinaryLen = sqlite3_decode_binary(mpBuf, mpBuf);

		if (mnBinaryLen == -1)
		{
			throw CppSQLite3Exception(CPPSQLITE_ERROR,
									"Cannot decode binary",
									DONT_DELETE_MSG);
		}

		mbEncoded = false;
	}

	return mpBuf;
}


int CppSQLite3Binary::getBinaryLength()
{
	getBinary();
	return mnBinaryLen;
}


unsigned char* CppSQLite3Binary::allocBuffer(int nLen)
{
	clear();

	// Allow extra space for encoded binary as per comments in
	// SQLite encode.c See bottom of this file for implementation
	// of SQLite functions use 3 instead of 2 just to be sure ;-)
	mnBinaryLen = nLen;
	mnBufferLen = 3 + (257*nLen)/254;

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	mbEncoded = false;

	return mpBuf;
}


void CppSQLite3Binary::clear()
{
	if (mpBuf)
	{
		mnBinaryLen = 0;
		mnBufferLen = 0;
		free(mpBuf);
		mpBuf = 0;
	}
}




CppSQLite3Query::CppSQLite3Query()
{
	mpVM = 0;
	mbEof = true;
	mnCols = 0;
	mbOwnVM = false;
}


CppSQLite3Query::CppSQLite3Query(const CppSQLite3Query& rQuery)
{
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLite3Query&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mbOwnVM = rQuery.mbOwnVM;
}


CppSQLite3Query::CppSQLite3Query(sqlite3* pDB,
							sqlite3_stmt* pVM,
							bool bEof,
							bool bOwnVM/*=true*/)
{
	mpDB = pDB;
	mpVM = pVM;
	mbEof = bEof;
	mnCols = sqlite3_column_count(mpVM);
	mbOwnVM = bOwnVM;
}


CppSQLite3Query::~CppSQLite3Query()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Query& CppSQLite3Query::operator=(const CppSQLite3Query& rQuery)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLite3Query&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mbOwnVM = rQuery.mbOwnVM;
	return *this;
}


int CppSQLite3Query::numFields()
{
	checkVM();
	return mnCols;
}


const char* CppSQLite3Query::fieldValue(int nField)
{
	checkVM();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return (const char*)sqlite3_column_text(mpVM, nField);
}


const char* CppSQLite3Query::fieldValue(const char* szField)
{
	int nField = fieldIndex(szField);
	return (const char*)sqlite3_column_text(mpVM, nField);
}


int CppSQLite3Query::getIntField(int nField, int nNullValue/*=0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return nNullValue;
	}
	else
	{
		return sqlite3_column_int(mpVM, nField);
	}
}


int CppSQLite3Query::getIntField(const char* szField, int nNullValue/*=0*/)
{
	int nField = fieldIndex(szField);
	return getIntField(nField, nNullValue);
}


sqlite_int64 CppSQLite3Query::getInt64Field(int nField, sqlite_int64 nNullValue/*=0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return nNullValue;
	}
	else
	{
		return sqlite3_column_int64(mpVM, nField);
	}
}


sqlite_int64 CppSQLite3Query::getInt64Field(const char* szField, sqlite_int64 nNullValue/*=0*/)
{
	int nField = fieldIndex(szField);
	return getInt64Field(nField, nNullValue);
}


double CppSQLite3Query::getFloatField(int nField, double fNullValue/*=0.0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return fNullValue;
	}
	else
	{
		return sqlite3_column_double(mpVM, nField);
	}
}


double CppSQLite3Query::getFloatField(const char* szField, double fNullValue/*=0.0*/)
{
	int nField = fieldIndex(szField);
	return getFloatField(nField, fNullValue);
}


const char* CppSQLite3Query::getStringField(int nField, const char* szNullValue/*=""*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return szNullValue;
	}
	else
	{
		return (const char*)sqlite3_column_text(mpVM, nField);
	}
}


const char* CppSQLite3Query::getStringField(const char* szField, const char* szNullValue/*=""*/)
{
	int nField = fieldIndex(szField);
	return getStringField(nField, szNullValue);
}


const unsigned char* CppSQLite3Query::getBlobField(int nField, int& nLen)
{
	checkVM();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	nLen = sqlite3_column_bytes(mpVM, nField);
	return (const unsigned char*)sqlite3_column_blob(mpVM, nField);
}


const unsigned char* CppSQLite3Query::getBlobField(const char* szField, int& nLen)
{
	int nField = fieldIndex(szField);
	return getBlobField(nField, nLen);
}


bool CppSQLite3Query::fieldIsNull(int nField)
{
	return (fieldDataType(nField) == SQLITE_NULL);
}


bool CppSQLite3Query::fieldIsNull(const char* szField)
{
	int nField = fieldIndex(szField);
	return (fieldDataType(nField) == SQLITE_NULL);
}


int CppSQLite3Query::fieldIndex(const char* szField)
{
	checkVM();

	if (szField)
	{
		for (int nField = 0; nField < mnCols; nField++)
		{
			const char* szTemp = sqlite3_column_name(mpVM, nField);

			if (strcmp(szField, szTemp) == 0)
			{
				return nField;
			}
		}
	}

	throw CppSQLite3Exception(CPPSQLITE_ERROR,
							"Invalid field name requested",
							DONT_DELETE_MSG);
}


const char* CppSQLite3Query::fieldName(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_name(mpVM, nCol);
}


const char* CppSQLite3Query::fieldDeclType(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_decltype(mpVM, nCol);
}


int CppSQLite3Query::fieldDataType(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_type(mpVM, nCol);
}


bool CppSQLite3Query::eof()
{
	checkVM();
	return mbEof;
}


void CppSQLite3Query::nextRow()
{
	checkVM();

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		mbEof = true;
	}
	else if (nRet == SQLITE_ROW)
	{
		// more rows, nothing to do
	}
	else
	{
		nRet = sqlite3_finalize(mpVM);
		mpVM = 0;
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet,
								(char*)szError,
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Query::finalize()
{
	if (mpVM && mbOwnVM)
	{
		int nRet = sqlite3_finalize(mpVM);
		mpVM = 0;
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Query::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3Table::CppSQLite3Table()
{
	mpaszResults = 0;
	mnRows = 0;
	mnCols = 0;
	mnCurrentRow = 0;
}


CppSQLite3Table::CppSQLite3Table(const CppSQLite3Table& rTable)
{
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLite3Table&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
}


CppSQLite3Table::CppSQLite3Table(char** paszResults, int nRows, int nCols)
{
	mpaszResults = paszResults;
	mnRows = nRows;
	mnCols = nCols;
	mnCurrentRow = 0;
}


CppSQLite3Table::~CppSQLite3Table()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Table& CppSQLite3Table::operator=(const CppSQLite3Table& rTable)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLite3Table&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
	return *this;
}


void CppSQLite3Table::finalize()
{
	if (mpaszResults)
	{
		sqlite3_free_table(mpaszResults);
		mpaszResults = 0;
	}
}


int CppSQLite3Table::numFields()
{
	checkResults();
	return mnCols;
}


int CppSQLite3Table::numRows()
{
	checkResults();
	return mnRows;
}


const char* CppSQLite3Table::fieldValue(int nField)
{
	checkResults();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	int nIndex = (mnCurrentRow*mnCols) + mnCols + nField;
	return mpaszResults[nIndex];
}


const char* CppSQLite3Table::fieldValue(const char* szField)
{
	checkResults();

	if (szField)
	{
		for (int nField = 0; nField < mnCols; nField++)
		{
			if (strcmp(szField, mpaszResults[nField]) == 0)
			{
				int nIndex = (mnCurrentRow*mnCols) + mnCols + nField;
				return mpaszResults[nIndex];
			}
		}
	}

	throw CppSQLite3Exception(CPPSQLITE_ERROR,
							"Invalid field name requested",
							DONT_DELETE_MSG);
}


int CppSQLite3Table::getIntField(int nField, int nNullValue/*=0*/)
{
	if (fieldIsNull(nField))
	{
		return nNullValue;
	}
	else
	{
		return atoi(fieldValue(nField));
	}
}


int CppSQLite3Table::getIntField(const char* szField, int nNullValue/*=0*/)
{
	if (fieldIsNull(szField))
	{
		return nNullValue;
	}
	else
	{
		return atoi(fieldValue(szField));
	}
}


double CppSQLite3Table::getFloatField(int nField, double fNullValue/*=0.0*/)
{
	if (fieldIsNull(nField))
	{
		return fNullValue;
	}
	else
	{
		return atof(fieldValue(nField));
	}
}


double CppSQLite3Table::getFloatField(const char* szField, double fNullValue/*=0.0*/)
{
	if (fieldIsNull(szField))
	{
		return fNullValue;
	}
	else
	{
		return atof(fieldValue(szField));
	}
}


const char* CppSQLite3Table::getStringField(int nField, const char* szNullValue/*=""*/)
{
	if (fieldIsNull(nField))
	{
		return szNullValue;
	}
	else
	{
		return fieldValue(nField);
	}
}


const char* CppSQLite3Table::getStringField(const char* szField, const char* szNullValue/*=""*/)
{
	if (fieldIsNull(szField))
	{
		return szNullValue;
	}
	else
	{
		return fieldValue(szField);
	}
}


bool CppSQLite3Table::fieldIsNull(int nField)
{
	checkResults();
	return (fieldValue(nField) == 0);
}


bool CppSQLite3Table::fieldIsNull(const char* szField)
{
	checkResults();
	return (fieldValue(szField) == 0);
}


const char* CppSQLite3Table::fieldName(int nCol)
{
	checkResults();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszResults[nCol];
}


void CppSQLite3Table::setRow(int nRow)
{
	checkResults();

	if (nRow < 0 || nRow > mnRows-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid row index requested",
								DONT_DELETE_MSG);
	}

	mnCurrentRow = nRow;
}


void CppSQLite3Table::checkResults()
{
	if (mpaszResults == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Results pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3Statement::CppSQLite3Statement()
{
	mpDB = 0;
	mpVM = 0;
}


CppSQLite3Statement::CppSQLite3Statement(const CppSQLite3Statement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLite3Statement&>(rStatement).mpVM = 0;
}


CppSQLite3Statement::CppSQLite3Statement(sqlite3* pDB, sqlite3_stmt* pVM)
{
	mpDB = pDB;
	mpVM = pVM;
}


CppSQLite3Statement::~CppSQLite3Statement()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Statement& CppSQLite3Statement::operator=(const CppSQLite3Statement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLite3Statement&>(rStatement).mpVM = 0;
	return *this;
}


int CppSQLite3Statement::execDML()
{
	checkDB();
	checkVM();

	const char* szError=0;

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		int nRowsChanged = sqlite3_changes(mpDB);

		nRet = sqlite3_reset(mpVM);

		if (nRet != SQLITE_OK)
		{
			szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}

		return nRowsChanged;
	}
	else
	{
		nRet = sqlite3_reset(mpVM);
		szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


CppSQLite3Query CppSQLite3Statement::execQuery()
{
	checkDB();
	checkVM();

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLite3Query(mpDB, mpVM, true/*eof*/, false);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLite3Query(mpDB, mpVM, false/*eof*/, false);
	}
	else
	{
		nRet = sqlite3_reset(mpVM);
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const char* szValue)
{
	checkVM();
	int nRes = sqlite3_bind_text(mpVM, nParam, szValue, -1, SQLITE_TRANSIENT);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding string param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const int nValue)
{
	checkVM();
	int nRes = sqlite3_bind_int(mpVM, nParam, nValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding int param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const double dValue)
{
	checkVM();
	int nRes = sqlite3_bind_double(mpVM, nParam, dValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding double param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const unsigned char* blobValue, int nLen)
{
	checkVM();
	int nRes = sqlite3_bind_blob(mpVM, nParam,
								(const void*)blobValue, nLen, SQLITE_TRANSIENT);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding blob param",
								DONT_DELETE_MSG);
	}
}

	
void CppSQLite3Statement::bind(int nParam, const sqlite_int64 nValue)
{
	checkVM();
	int nRes = sqlite3_bind_int64(mpVM, nParam, nValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
			"Error binding int64 param",
			DONT_DELETE_MSG);
	}
}

void CppSQLite3Statement::bindNull(int nParam)
{
	checkVM();
	int nRes = sqlite3_bind_null(mpVM, nParam);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding NULL param",
								DONT_DELETE_MSG);
	}
}


int CppSQLite3Statement::bindParameterIndex(const char* szParam)
{
	checkVM();

	int nParam = sqlite3_bind_parameter_index(mpVM, szParam);

int nn = sqlite3_bind_parameter_count(mpVM);
const char* sz1 = sqlite3_bind_parameter_name(mpVM, 1);
const char* sz2 = sqlite3_bind_parameter_name(mpVM, 2);

	if (!nParam)
	{
		char buf[128];
		sprintf(buf, "Parameter '%s' is not valid for this statement", szParam);
		throw CppSQLite3Exception(CPPSQLITE_ERROR, buf, DONT_DELETE_MSG);
	}

	return nParam;
}


void CppSQLite3Statement::bind(const char* szParam, const char* szValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, szValue);
}


void CppSQLite3Statement::bind(const char* szParam, const int nValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, nValue);
}

void CppSQLite3Statement::bind(const char* szParam, const double dwValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, dwValue);
}

void CppSQLite3Statement::bind(const char* szParam, const unsigned char* blobValue, int nLen)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, blobValue, nLen);
}


void CppSQLite3Statement::bindNull(const char* szParam)
{
	int nParam = bindParameterIndex(szParam);
	bindNull(nParam);
}


void CppSQLite3Statement::reset()
{
	if (mpVM)
	{
		int nRet = sqlite3_reset(mpVM);

		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Statement::finalize()
{
	if (mpVM)
	{
		int nRet = sqlite3_finalize(mpVM);
		mpVM = 0;

		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Statement::checkDB()
{
	if (mpDB == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3DB::CppSQLite3DB()
{
	mpDB = 0;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLite3DB::CppSQLite3DB(const CppSQLite3DB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLite3DB::~CppSQLite3DB()
{
	try
	{
		close();
	}
	catch (...)
	{
	}
}


CppSQLite3DB& CppSQLite3DB::operator=(const CppSQLite3DB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
	return *this;
}


// void CppSQLite3DB::open(const char* szFile)
// {
// 	int nRet = sqlite3_open(szFile, &mpDB);
// 
// 	if (nRet != SQLITE_OK)
// 	{
// 		const char* szError = sqlite3_errmsg(mpDB);
// 		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
// 	}
// 
// 	setBusyTimeout(mnBusyTimeoutMs);
// }


void CppSQLite3DB::open(const char* szFile, const char* szPwd/* = nullptr*/)
{
	int nRet = sqlite3_open(szFile, &mpDB);

	if (nRet != SQLITE_OK)
	{
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}

	setBusyTimeout(mnBusyTimeoutMs);

	if (szPwd && strlen(szPwd) > 0) {
		nRet = sqlite3_key_v2(mpDB, "main", szPwd, std::strlen(szPwd));
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}

void CppSQLite3DB::password(const char* szPwd /*= nullptr*/)
{
	if (mpDB)
	{
		int nRet = sqlite3_rekey_v2(mpDB, "main", szPwd, szPwd == nullptr ? 0 : std::strlen(szPwd));
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}

void CppSQLite3DB::close()
{
	if (mpDB)
	{
		if (sqlite3_close(mpDB) == SQLITE_OK)
		{
			mpDB = 0;
		}
		else
		{
			throw CppSQLite3Exception(CPPSQLITE_ERROR,
									"Unable to close database",
									DONT_DELETE_MSG);
		}
	}
}


CppSQLite3Statement CppSQLite3DB::compileStatement(const char* szSQL)
{
	checkDB();

	sqlite3_stmt* pVM = compile(szSQL);
	return CppSQLite3Statement(mpDB, pVM);
}


bool CppSQLite3DB::tableExists(const char* szTable)
{
	char szSQL[256];
	sprintf(szSQL,
			"select count(*) from sqlite_master where (type='table' or type='view' or type='trigger' or type='index') and name='%s'",
			szTable);
	int nRet = execScalar(szSQL);
	return (nRet > 0);
}


int CppSQLite3DB::execDML(const char* szSQL)
{
	checkDB();

	char* szError=0;

	int nRet = sqlite3_exec(mpDB, szSQL, 0, 0, &szError);

	if (nRet == SQLITE_OK)
	{
		return sqlite3_changes(mpDB);
	}
	else
	{
		throw CppSQLite3Exception(nRet, szError);
	}
}


CppSQLite3Query CppSQLite3DB::execQuery(const char* szSQL)
{
	checkDB();

	sqlite3_stmt* pVM = compile(szSQL);

	int nRet = sqlite3_step(pVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLite3Query(mpDB, pVM, true/*eof*/);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLite3Query(mpDB, pVM, false/*eof*/);
	}
	else
	{
		nRet = sqlite3_finalize(pVM);
		const char* szError= sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


int CppSQLite3DB::execScalar(const char* szSQL, int nNullValue/*=0*/)
{
	CppSQLite3Query q = execQuery(szSQL);

	if (q.eof() || q.numFields() < 1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid scalar query",
								DONT_DELETE_MSG);
	}

	return q.getIntField(0, nNullValue);
}


CppSQLite3Table CppSQLite3DB::getTable(const char* szSQL)
{
	checkDB();

	char* szError=0;
	char** paszResults=0;
	int nRet;
	int nRows(0);
	int nCols(0);

	nRet = sqlite3_get_table(mpDB, szSQL, &paszResults, &nRows, &nCols, &szError);

	if (nRet == SQLITE_OK)
	{
		return CppSQLite3Table(paszResults, nRows, nCols);
	}
	else
	{
		throw CppSQLite3Exception(nRet, szError);
	}
}


sqlite_int64 CppSQLite3DB::lastRowId()
{
	return sqlite3_last_insert_rowid(mpDB);
}


void CppSQLite3DB::setBusyTimeout(int nMillisecs)
{
	mnBusyTimeoutMs = nMillisecs;
	sqlite3_busy_timeout(mpDB, mnBusyTimeoutMs);
}


void CppSQLite3DB::checkDB()
{
	if (!mpDB)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


sqlite3_stmt* CppSQLite3DB::compile(const char* szSQL)
{
	checkDB();

	const char* szTail=0;
	sqlite3_stmt* pVM;

	int nRet = sqlite3_prepare_v2(mpDB, szSQL, -1, &pVM, &szTail);

	if (nRet != SQLITE_OK)
	{
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet,
								(char*)szError,
								DONT_DELETE_MSG);
	}

	return pVM;
}

bool CppSQLite3DB::IsAutoCommitOn()
{
	checkDB();
	return sqlite3_get_autocommit(mpDB) ? true : false;
}


// SQLite encode.c reproduced here, containing implementation notes and source
// for sqlite3_encode_binary() and sqlite3_decode_binary() 


/*
** 2002 April 25
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains helper routines used to translate binary data into
** a null-terminated string (suitable for use in SQLite) and back again.
** These are convenience routines for use by people who want to store binary
** data in an SQLite database.  The code in this file is not used by any other
** part of the SQLite library.
**
** $Id: encode.c,v 1.10 2004/01/14 21:59:23 drh Exp $
*/

/*
** How This Encoder Works
**
** The output is allowed to contain any character except 0x27 (') and
** 0x00.  This is accomplished by using an escape character to encode
** 0x27 and 0x00 as a two-byte sequence.  The escape character is always
** 0x01.  An 0x00 is encoded as the two byte sequence 0x01 0x01.  The
** 0x27 character is encoded as the two byte sequence 0x01 0x03.  Finally,
** the escape character itself is encoded as the two-character sequence
** 0x01 0x02.
**
** To summarize, the encoder works by using an escape sequences as follows:
**
**       0x00  ->  0x01 0x01
**       0x01  ->  0x01 0x02
**       0x27  ->  0x01 0x03
**
** If that were all the encoder did, it would work, but in certain cases
** it could double the size of the encoded string.  For example, to
** encode a string of 100 0x27 characters would require 100 instances of
** the 0x01 0x03 escape sequence resulting in a 200-character output.
** We would prefer to keep the size of the encoded string smaller than
** this.
**
** To minimize the encoding size, we first add a fixed offset value to each 
** byte in the sequence.  The addition is modulo 256.  (That is to say, if
** the sum of the original character value and the offset exceeds 256, then
** the higher order bits are truncated.)  The offset is chosen to minimize
** the number of characters in the string that need to be escaped.  For
** example, in the case above where the string was composed of 100 0x27
** characters, the offset might be 0x01.  Each of the 0x27 characters would
** then be converted into an 0x28 character which would not need to be
** escaped at all and so the 100 character input string would be converted
** into just 100 characters of output.  Actually 101 characters of output - 
** we have to record the offset used as the first byte in the sequence so
** that the string can be decoded.  Since the offset value is stored as
** part of the output string and the output string is not allowed to contain
** characters 0x00 or 0x27, the offset cannot be 0x00 or 0x27.
**
** Here, then, are the encoding steps:
**
**     (1)   Choose an offset value and make it the first character of
**           output.
**
**     (2)   Copy each input character into the output buffer, one by
**           one, adding the offset value as you copy.
**
**     (3)   If the value of an input character plus offset is 0x00, replace
**           that one character by the two-character sequence 0x01 0x01.
**           If the sum is 0x01, replace it with 0x01 0x02.  If the sum
**           is 0x27, replace it with 0x01 0x03.
**
**     (4)   Put a 0x00 terminator at the end of the output.
**
** Decoding is obvious:
**
**     (5)   Copy encoded characters except the first into the decode 
**           buffer.  Set the first encoded character aside for use as
**           the offset in step 7 below.
**
**     (6)   Convert each 0x01 0x01 sequence into a single character 0x00.
**           Convert 0x01 0x02 into 0x01.  Convert 0x01 0x03 into 0x27.
**
**     (7)   Subtract the offset value that was the first character of
**           the encoded buffer from all characters in the output buffer.
**
** The only tricky part is step (1) - how to compute an offset value to
** minimize the size of the output buffer.  This is accomplished by testing
** all offset values and picking the one that results in the fewest number
** of escapes.  To do that, we first scan the entire input and count the
** number of occurances of each character value in the input.  Suppose
** the number of 0x00 characters is N(0), the number of occurances of 0x01
** is N(1), and so forth up to the number of occurances of 0xff is N(255).
** An offset of 0 is not allowed so we don't have to test it.  The number
** of escapes required for an offset of 1 is N(1)+N(2)+N(40).  The number
** of escapes required for an offset of 2 is N(2)+N(3)+N(41).  And so forth.
** In this way we find the offset that gives the minimum number of escapes,
** and thus minimizes the length of the output string.
*/

/*
** Encode a binary buffer "in" of size n bytes so that it contains
** no instances of characters '\'' or '\000'.  The output is 
** null-terminated and can be used as a string value in an INSERT
** or UPDATE statement.  Use sqlite3_decode_binary() to convert the
** string back into its original binary.
**
** The result is written into a preallocated output buffer "out".
** "out" must be able to hold at least 2 +(257*n)/254 bytes.
** In other words, the output will be expanded by as much as 3
** bytes for every 254 bytes of input plus 2 bytes of fixed overhead.
** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.)
**
** The return value is the number of characters in the encoded
** string, excluding the "\000" terminator.
*/
int sqlite3_encode_binary(const unsigned char *in, int n, unsigned char *out){
  int i, j, e, m;
  int cnt[256];
  if( n<=0 ){
    out[0] = 'x';
    out[1] = 0;
    return 1;
  }
  memset(cnt, 0, sizeof(cnt));
  for(i=n-1; i>=0; i--){ cnt[in[i]]++; }
  m = n;
  for(i=1; i<256; i++){
    int sum;
    if( i=='\'' ) continue;
    sum = cnt[i] + cnt[(i+1)&0xff] + cnt[(i+'\'')&0xff];
    if( sum<m ){
      m = sum;
      e = i;
      if( m==0 ) break;
    }
  }
  out[0] = e;
  j = 1;
  for(i=0; i<n; i++){
    int c = (in[i] - e)&0xff;
    if( c==0 ){
      out[j++] = 1;
      out[j++] = 1;
    }else if( c==1 ){
      out[j++] = 1;
      out[j++] = 2;
    }else if( c=='\'' ){
      out[j++] = 1;
      out[j++] = 3;
    }else{
      out[j++] = c;
    }
  }
  out[j] = 0;
  return j;
}

/*
** Decode the string "in" into binary data and write it into "out".
** This routine reverses the encoding created by sqlite3_encode_binary().
** The output will always be a few bytes less than the input.  The number
** of bytes of output is returned.  If the input is not a well-formed
** encoding, -1 is returned.
**
** The "in" and "out" parameters may point to the same buffer in order
** to decode a string in place.
*/
int sqlite3_decode_binary(const unsigned char *in, unsigned char *out){
  int i, c, e;
  e = *(in++);
  i = 0;
  while( (c = *(in++))!=0 ){
    if( c==1 ){
      c = *(in++);
      if( c==1 ){
        c = 0;
      }else if( c==2 ){
        c = 1;
      }else if( c==3 ){
        c = '\'';
      }else{
        return -1;
      }
    }
    out[i++] = (c + e)&0xff;
  }
  return i;
}
  • CppSQLite3.cpp
// CppSQLite3 - A C++ wrapper around the SQLite3 embedded database library.
//
// Copyright (c) 2004..2007 Rob Groves. All Rights Reserved. rob.groves@btinternet.com
// 
// Permission to use, copy, modify, and distribute this software and its
// documentation for any purpose, without fee, and without a written
// agreement, is hereby granted, provided that the above copyright notice, 
// this paragraph and the following two paragraphs appear in all copies, 
// modifications, and distributions.
//
// IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
// INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST
// PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION,
// EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF
// ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". THE AUTHOR HAS NO OBLIGATION
// TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
//
// V3.0		03/08/2004	-Initial Version for sqlite3
//
// V3.1		16/09/2004	-Implemented getXXXXField using sqlite3 functions
//						-Added CppSQLiteDB3::tableExists()
//
// V3.2		01/07/2005	-Fixed execScalar to handle a NULL result
//			12/07/2007	-Added int64 functions to CppSQLite3Query
//						-Throw exception from CppSQLite3DB::close() if error
//						-Trap above exception in CppSQLite3DB::~CppSQLite3DB()
//						-Fix to CppSQLite3DB::compile() as provided by Dave Rollins.
//						-sqlite3_prepare replaced with sqlite3_prepare_v2
//						-Added Name based parameter binding to CppSQLite3Statement.

#include "CppSQLite3.h"
#include <cstdlib>


// Named constant for passing to CppSQLite3Exception when passing it a string
// that cannot be deleted.
static const bool DONT_DELETE_MSG=false;


// Prototypes for SQLite functions not included in SQLite DLL, but copied below
// from SQLite encode.c

int sqlite3_encode_binary(const unsigned char *in, int n, unsigned char *out);
int sqlite3_decode_binary(const unsigned char *in, unsigned char *out);





CppSQLite3Exception::CppSQLite3Exception(const int nErrCode,
									const char* szErrMess,
									bool bDeleteMsg/*=true*/) :
									mnErrCode(nErrCode)
{
	mpszErrMess = sqlite3_mprintf("%s[%d]: %s",
								errorCodeAsString(nErrCode),
								nErrCode,
								szErrMess ? szErrMess : "");

	if (bDeleteMsg && szErrMess)
	{
		sqlite3_free((void*)szErrMess);
	}
}

									
CppSQLite3Exception::CppSQLite3Exception(const CppSQLite3Exception&  e) :
									mnErrCode(e.mnErrCode)
{
	mpszErrMess = 0;
	if (e.mpszErrMess)
	{
		mpszErrMess = sqlite3_mprintf("%s", e.mpszErrMess);
	}
}


const char* CppSQLite3Exception::errorCodeAsString(int nErrCode)
{
	switch (nErrCode)
	{
		case SQLITE_OK          : return "SQLITE_OK";
		case SQLITE_ERROR       : return "SQLITE_ERROR";
		case SQLITE_INTERNAL    : return "SQLITE_INTERNAL";
		case SQLITE_PERM        : return "SQLITE_PERM";
		case SQLITE_ABORT       : return "SQLITE_ABORT";
		case SQLITE_BUSY        : return "SQLITE_BUSY";
		case SQLITE_LOCKED      : return "SQLITE_LOCKED";
		case SQLITE_NOMEM       : return "SQLITE_NOMEM";
		case SQLITE_READONLY    : return "SQLITE_READONLY";
		case SQLITE_INTERRUPT   : return "SQLITE_INTERRUPT";
		case SQLITE_IOERR       : return "SQLITE_IOERR";
		case SQLITE_CORRUPT     : return "SQLITE_CORRUPT";
		case SQLITE_NOTFOUND    : return "SQLITE_NOTFOUND";
		case SQLITE_FULL        : return "SQLITE_FULL";
		case SQLITE_CANTOPEN    : return "SQLITE_CANTOPEN";
		case SQLITE_PROTOCOL    : return "SQLITE_PROTOCOL";
		case SQLITE_EMPTY       : return "SQLITE_EMPTY";
		case SQLITE_SCHEMA      : return "SQLITE_SCHEMA";
		case SQLITE_TOOBIG      : return "SQLITE_TOOBIG";
		case SQLITE_CONSTRAINT  : return "SQLITE_CONSTRAINT";
		case SQLITE_MISMATCH    : return "SQLITE_MISMATCH";
		case SQLITE_MISUSE      : return "SQLITE_MISUSE";
		case SQLITE_NOLFS       : return "SQLITE_NOLFS";
		case SQLITE_AUTH        : return "SQLITE_AUTH";
		case SQLITE_FORMAT      : return "SQLITE_FORMAT";
		case SQLITE_RANGE       : return "SQLITE_RANGE";
		case SQLITE_ROW         : return "SQLITE_ROW";
		case SQLITE_DONE        : return "SQLITE_DONE";
		case CPPSQLITE_ERROR    : return "CPPSQLITE_ERROR";
		default: return "UNKNOWN_ERROR";
	}
}


CppSQLite3Exception::~CppSQLite3Exception()
{
	if (mpszErrMess)
	{
		sqlite3_free(mpszErrMess);
		mpszErrMess = 0;
	}
}




CppSQLite3Buffer::CppSQLite3Buffer()
{
	mpBuf = 0;
}


CppSQLite3Buffer::~CppSQLite3Buffer()
{
	clear();
}


void CppSQLite3Buffer::clear()
{
	if (mpBuf)
	{
		sqlite3_free(mpBuf);
		mpBuf = 0;
	}

}


const char* CppSQLite3Buffer::format(const char* szFormat, ...)
{
	clear();
	va_list va;
	va_start(va, szFormat);
	mpBuf = sqlite3_vmprintf(szFormat, va);
	va_end(va);
	return mpBuf;
}




CppSQLite3Binary::CppSQLite3Binary() :
						mpBuf(0),
						mnBinaryLen(0),
						mnBufferLen(0),
						mnEncodedLen(0),
						mbEncoded(false)
{
}


CppSQLite3Binary::~CppSQLite3Binary()
{
	clear();
}


void CppSQLite3Binary::setBinary(const unsigned char* pBuf, int nLen)
{
	mpBuf = allocBuffer(nLen);
	memcpy(mpBuf, pBuf, nLen);
}


void CppSQLite3Binary::setEncoded(const unsigned char* pBuf)
{
	clear();

	mnEncodedLen = strlen((const char*)pBuf);
	mnBufferLen = mnEncodedLen + 1; // Allow for NULL terminator

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	memcpy(mpBuf, pBuf, mnBufferLen);
	mbEncoded = true;
}


const unsigned char* CppSQLite3Binary::getEncoded()
{
	if (!mbEncoded)
	{
		unsigned char* ptmp = (unsigned char*)malloc(mnBinaryLen);
		memcpy(ptmp, mpBuf, mnBinaryLen);
		mnEncodedLen = sqlite3_encode_binary(ptmp, mnBinaryLen, mpBuf);
		free(ptmp);
		mbEncoded = true;
	}

	return mpBuf;
}


const unsigned char* CppSQLite3Binary::getBinary()
{
	if (mbEncoded)
	{
		// in/out buffers can be the same
		mnBinaryLen = sqlite3_decode_binary(mpBuf, mpBuf);

		if (mnBinaryLen == -1)
		{
			throw CppSQLite3Exception(CPPSQLITE_ERROR,
									"Cannot decode binary",
									DONT_DELETE_MSG);
		}

		mbEncoded = false;
	}

	return mpBuf;
}


int CppSQLite3Binary::getBinaryLength()
{
	getBinary();
	return mnBinaryLen;
}


unsigned char* CppSQLite3Binary::allocBuffer(int nLen)
{
	clear();

	// Allow extra space for encoded binary as per comments in
	// SQLite encode.c See bottom of this file for implementation
	// of SQLite functions use 3 instead of 2 just to be sure ;-)
	mnBinaryLen = nLen;
	mnBufferLen = 3 + (257*nLen)/254;

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	mbEncoded = false;

	return mpBuf;
}


void CppSQLite3Binary::clear()
{
	if (mpBuf)
	{
		mnBinaryLen = 0;
		mnBufferLen = 0;
		free(mpBuf);
		mpBuf = 0;
	}
}




CppSQLite3Query::CppSQLite3Query()
{
	mpVM = 0;
	mbEof = true;
	mnCols = 0;
	mbOwnVM = false;
}


CppSQLite3Query::CppSQLite3Query(const CppSQLite3Query& rQuery)
{
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLite3Query&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mbOwnVM = rQuery.mbOwnVM;
}


CppSQLite3Query::CppSQLite3Query(sqlite3* pDB,
							sqlite3_stmt* pVM,
							bool bEof,
							bool bOwnVM/*=true*/)
{
	mpDB = pDB;
	mpVM = pVM;
	mbEof = bEof;
	mnCols = sqlite3_column_count(mpVM);
	mbOwnVM = bOwnVM;
}


CppSQLite3Query::~CppSQLite3Query()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Query& CppSQLite3Query::operator=(const CppSQLite3Query& rQuery)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLite3Query&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mbOwnVM = rQuery.mbOwnVM;
	return *this;
}


int CppSQLite3Query::numFields()
{
	checkVM();
	return mnCols;
}


const char* CppSQLite3Query::fieldValue(int nField)
{
	checkVM();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return (const char*)sqlite3_column_text(mpVM, nField);
}


const char* CppSQLite3Query::fieldValue(const char* szField)
{
	int nField = fieldIndex(szField);
	return (const char*)sqlite3_column_text(mpVM, nField);
}


int CppSQLite3Query::getIntField(int nField, int nNullValue/*=0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return nNullValue;
	}
	else
	{
		return sqlite3_column_int(mpVM, nField);
	}
}


int CppSQLite3Query::getIntField(const char* szField, int nNullValue/*=0*/)
{
	int nField = fieldIndex(szField);
	return getIntField(nField, nNullValue);
}


sqlite_int64 CppSQLite3Query::getInt64Field(int nField, sqlite_int64 nNullValue/*=0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return nNullValue;
	}
	else
	{
		return sqlite3_column_int64(mpVM, nField);
	}
}


sqlite_int64 CppSQLite3Query::getInt64Field(const char* szField, sqlite_int64 nNullValue/*=0*/)
{
	int nField = fieldIndex(szField);
	return getInt64Field(nField, nNullValue);
}


double CppSQLite3Query::getFloatField(int nField, double fNullValue/*=0.0*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return fNullValue;
	}
	else
	{
		return sqlite3_column_double(mpVM, nField);
	}
}


double CppSQLite3Query::getFloatField(const char* szField, double fNullValue/*=0.0*/)
{
	int nField = fieldIndex(szField);
	return getFloatField(nField, fNullValue);
}


const char* CppSQLite3Query::getStringField(int nField, const char* szNullValue/*=""*/)
{
	if (fieldDataType(nField) == SQLITE_NULL)
	{
		return szNullValue;
	}
	else
	{
		return (const char*)sqlite3_column_text(mpVM, nField);
	}
}


const char* CppSQLite3Query::getStringField(const char* szField, const char* szNullValue/*=""*/)
{
	int nField = fieldIndex(szField);
	return getStringField(nField, szNullValue);
}


const unsigned char* CppSQLite3Query::getBlobField(int nField, int& nLen)
{
	checkVM();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	nLen = sqlite3_column_bytes(mpVM, nField);
	return (const unsigned char*)sqlite3_column_blob(mpVM, nField);
}


const unsigned char* CppSQLite3Query::getBlobField(const char* szField, int& nLen)
{
	int nField = fieldIndex(szField);
	return getBlobField(nField, nLen);
}


bool CppSQLite3Query::fieldIsNull(int nField)
{
	return (fieldDataType(nField) == SQLITE_NULL);
}


bool CppSQLite3Query::fieldIsNull(const char* szField)
{
	int nField = fieldIndex(szField);
	return (fieldDataType(nField) == SQLITE_NULL);
}


int CppSQLite3Query::fieldIndex(const char* szField)
{
	checkVM();

	if (szField)
	{
		for (int nField = 0; nField < mnCols; nField++)
		{
			const char* szTemp = sqlite3_column_name(mpVM, nField);

			if (strcmp(szField, szTemp) == 0)
			{
				return nField;
			}
		}
	}

	throw CppSQLite3Exception(CPPSQLITE_ERROR,
							"Invalid field name requested",
							DONT_DELETE_MSG);
}


const char* CppSQLite3Query::fieldName(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_name(mpVM, nCol);
}


const char* CppSQLite3Query::fieldDeclType(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_decltype(mpVM, nCol);
}


int CppSQLite3Query::fieldDataType(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return sqlite3_column_type(mpVM, nCol);
}


bool CppSQLite3Query::eof()
{
	checkVM();
	return mbEof;
}


void CppSQLite3Query::nextRow()
{
	checkVM();

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		mbEof = true;
	}
	else if (nRet == SQLITE_ROW)
	{
		// more rows, nothing to do
	}
	else
	{
		nRet = sqlite3_finalize(mpVM);
		mpVM = 0;
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet,
								(char*)szError,
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Query::finalize()
{
	if (mpVM && mbOwnVM)
	{
		int nRet = sqlite3_finalize(mpVM);
		mpVM = 0;
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Query::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3Table::CppSQLite3Table()
{
	mpaszResults = 0;
	mnRows = 0;
	mnCols = 0;
	mnCurrentRow = 0;
}


CppSQLite3Table::CppSQLite3Table(const CppSQLite3Table& rTable)
{
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLite3Table&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
}


CppSQLite3Table::CppSQLite3Table(char** paszResults, int nRows, int nCols)
{
	mpaszResults = paszResults;
	mnRows = nRows;
	mnCols = nCols;
	mnCurrentRow = 0;
}


CppSQLite3Table::~CppSQLite3Table()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Table& CppSQLite3Table::operator=(const CppSQLite3Table& rTable)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLite3Table&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
	return *this;
}


void CppSQLite3Table::finalize()
{
	if (mpaszResults)
	{
		sqlite3_free_table(mpaszResults);
		mpaszResults = 0;
	}
}


int CppSQLite3Table::numFields()
{
	checkResults();
	return mnCols;
}


int CppSQLite3Table::numRows()
{
	checkResults();
	return mnRows;
}


const char* CppSQLite3Table::fieldValue(int nField)
{
	checkResults();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	int nIndex = (mnCurrentRow*mnCols) + mnCols + nField;
	return mpaszResults[nIndex];
}


const char* CppSQLite3Table::fieldValue(const char* szField)
{
	checkResults();

	if (szField)
	{
		for (int nField = 0; nField < mnCols; nField++)
		{
			if (strcmp(szField, mpaszResults[nField]) == 0)
			{
				int nIndex = (mnCurrentRow*mnCols) + mnCols + nField;
				return mpaszResults[nIndex];
			}
		}
	}

	throw CppSQLite3Exception(CPPSQLITE_ERROR,
							"Invalid field name requested",
							DONT_DELETE_MSG);
}


int CppSQLite3Table::getIntField(int nField, int nNullValue/*=0*/)
{
	if (fieldIsNull(nField))
	{
		return nNullValue;
	}
	else
	{
		return atoi(fieldValue(nField));
	}
}


int CppSQLite3Table::getIntField(const char* szField, int nNullValue/*=0*/)
{
	if (fieldIsNull(szField))
	{
		return nNullValue;
	}
	else
	{
		return atoi(fieldValue(szField));
	}
}


double CppSQLite3Table::getFloatField(int nField, double fNullValue/*=0.0*/)
{
	if (fieldIsNull(nField))
	{
		return fNullValue;
	}
	else
	{
		return atof(fieldValue(nField));
	}
}


double CppSQLite3Table::getFloatField(const char* szField, double fNullValue/*=0.0*/)
{
	if (fieldIsNull(szField))
	{
		return fNullValue;
	}
	else
	{
		return atof(fieldValue(szField));
	}
}


const char* CppSQLite3Table::getStringField(int nField, const char* szNullValue/*=""*/)
{
	if (fieldIsNull(nField))
	{
		return szNullValue;
	}
	else
	{
		return fieldValue(nField);
	}
}


const char* CppSQLite3Table::getStringField(const char* szField, const char* szNullValue/*=""*/)
{
	if (fieldIsNull(szField))
	{
		return szNullValue;
	}
	else
	{
		return fieldValue(szField);
	}
}


bool CppSQLite3Table::fieldIsNull(int nField)
{
	checkResults();
	return (fieldValue(nField) == 0);
}


bool CppSQLite3Table::fieldIsNull(const char* szField)
{
	checkResults();
	return (fieldValue(szField) == 0);
}


const char* CppSQLite3Table::fieldName(int nCol)
{
	checkResults();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszResults[nCol];
}


void CppSQLite3Table::setRow(int nRow)
{
	checkResults();

	if (nRow < 0 || nRow > mnRows-1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid row index requested",
								DONT_DELETE_MSG);
	}

	mnCurrentRow = nRow;
}


void CppSQLite3Table::checkResults()
{
	if (mpaszResults == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Results pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3Statement::CppSQLite3Statement()
{
	mpDB = 0;
	mpVM = 0;
}


CppSQLite3Statement::CppSQLite3Statement(const CppSQLite3Statement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLite3Statement&>(rStatement).mpVM = 0;
}


CppSQLite3Statement::CppSQLite3Statement(sqlite3* pDB, sqlite3_stmt* pVM)
{
	mpDB = pDB;
	mpVM = pVM;
}


CppSQLite3Statement::~CppSQLite3Statement()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLite3Statement& CppSQLite3Statement::operator=(const CppSQLite3Statement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLite3Statement&>(rStatement).mpVM = 0;
	return *this;
}


int CppSQLite3Statement::execDML()
{
	checkDB();
	checkVM();

	const char* szError=0;

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		int nRowsChanged = sqlite3_changes(mpDB);

		nRet = sqlite3_reset(mpVM);

		if (nRet != SQLITE_OK)
		{
			szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}

		return nRowsChanged;
	}
	else
	{
		nRet = sqlite3_reset(mpVM);
		szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


CppSQLite3Query CppSQLite3Statement::execQuery()
{
	checkDB();
	checkVM();

	int nRet = sqlite3_step(mpVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLite3Query(mpDB, mpVM, true/*eof*/, false);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLite3Query(mpDB, mpVM, false/*eof*/, false);
	}
	else
	{
		nRet = sqlite3_reset(mpVM);
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const char* szValue)
{
	checkVM();
	int nRes = sqlite3_bind_text(mpVM, nParam, szValue, -1, SQLITE_TRANSIENT);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding string param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const int nValue)
{
	checkVM();
	int nRes = sqlite3_bind_int(mpVM, nParam, nValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding int param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const double dValue)
{
	checkVM();
	int nRes = sqlite3_bind_double(mpVM, nParam, dValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding double param",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::bind(int nParam, const unsigned char* blobValue, int nLen)
{
	checkVM();
	int nRes = sqlite3_bind_blob(mpVM, nParam,
								(const void*)blobValue, nLen, SQLITE_TRANSIENT);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding blob param",
								DONT_DELETE_MSG);
	}
}

	
void CppSQLite3Statement::bind(int nParam, const sqlite_int64 nValue)
{
	checkVM();
	int nRes = sqlite3_bind_int64(mpVM, nParam, nValue);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
			"Error binding int64 param",
			DONT_DELETE_MSG);
	}
}

void CppSQLite3Statement::bindNull(int nParam)
{
	checkVM();
	int nRes = sqlite3_bind_null(mpVM, nParam);

	if (nRes != SQLITE_OK)
	{
		throw CppSQLite3Exception(nRes,
								"Error binding NULL param",
								DONT_DELETE_MSG);
	}
}


int CppSQLite3Statement::bindParameterIndex(const char* szParam)
{
	checkVM();

	int nParam = sqlite3_bind_parameter_index(mpVM, szParam);

int nn = sqlite3_bind_parameter_count(mpVM);
const char* sz1 = sqlite3_bind_parameter_name(mpVM, 1);
const char* sz2 = sqlite3_bind_parameter_name(mpVM, 2);

	if (!nParam)
	{
		char buf[128];
		sprintf(buf, "Parameter '%s' is not valid for this statement", szParam);
		throw CppSQLite3Exception(CPPSQLITE_ERROR, buf, DONT_DELETE_MSG);
	}

	return nParam;
}


void CppSQLite3Statement::bind(const char* szParam, const char* szValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, szValue);
}


void CppSQLite3Statement::bind(const char* szParam, const int nValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, nValue);
}

void CppSQLite3Statement::bind(const char* szParam, const double dwValue)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, dwValue);
}

void CppSQLite3Statement::bind(const char* szParam, const unsigned char* blobValue, int nLen)
{
	int nParam = bindParameterIndex(szParam);
	bind(nParam, blobValue, nLen);
}


void CppSQLite3Statement::bindNull(const char* szParam)
{
	int nParam = bindParameterIndex(szParam);
	bindNull(nParam);
}


void CppSQLite3Statement::reset()
{
	if (mpVM)
	{
		int nRet = sqlite3_reset(mpVM);

		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Statement::finalize()
{
	if (mpVM)
	{
		int nRet = sqlite3_finalize(mpVM);
		mpVM = 0;

		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}


void CppSQLite3Statement::checkDB()
{
	if (mpDB == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


void CppSQLite3Statement::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}




CppSQLite3DB::CppSQLite3DB()
{
	mpDB = 0;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLite3DB::CppSQLite3DB(const CppSQLite3DB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLite3DB::~CppSQLite3DB()
{
	try
	{
		close();
	}
	catch (...)
	{
	}
}


CppSQLite3DB& CppSQLite3DB::operator=(const CppSQLite3DB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
	return *this;
}


// void CppSQLite3DB::open(const char* szFile)
// {
// 	int nRet = sqlite3_open(szFile, &mpDB);
// 
// 	if (nRet != SQLITE_OK)
// 	{
// 		const char* szError = sqlite3_errmsg(mpDB);
// 		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
// 	}
// 
// 	setBusyTimeout(mnBusyTimeoutMs);
// }


void CppSQLite3DB::open(const char* szFile, const char* szPwd/* = nullptr*/)
{
	int nRet = sqlite3_open(szFile, &mpDB);

	if (nRet != SQLITE_OK)
	{
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}

	setBusyTimeout(mnBusyTimeoutMs);

	if (szPwd && strlen(szPwd) > 0) {
		nRet = sqlite3_key_v2(mpDB, "main", szPwd, std::strlen(szPwd));
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}

void CppSQLite3DB::password(const char* szPwd /*= nullptr*/)
{
	if (mpDB)
	{
		int nRet = sqlite3_rekey_v2(mpDB, "main", szPwd, szPwd == nullptr ? 0 : std::strlen(szPwd));
		if (nRet != SQLITE_OK)
		{
			const char* szError = sqlite3_errmsg(mpDB);
			throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
		}
	}
}

void CppSQLite3DB::close()
{
	if (mpDB)
	{
		if (sqlite3_close(mpDB) == SQLITE_OK)
		{
			mpDB = 0;
		}
		else
		{
			throw CppSQLite3Exception(CPPSQLITE_ERROR,
									"Unable to close database",
									DONT_DELETE_MSG);
		}
	}
}


CppSQLite3Statement CppSQLite3DB::compileStatement(const char* szSQL)
{
	checkDB();

	sqlite3_stmt* pVM = compile(szSQL);
	return CppSQLite3Statement(mpDB, pVM);
}


bool CppSQLite3DB::tableExists(const char* szTable)
{
	char szSQL[256];
	sprintf(szSQL,
			"select count(*) from sqlite_master where (type='table' or type='view' or type='trigger' or type='index') and name='%s'",
			szTable);
	int nRet = execScalar(szSQL);
	return (nRet > 0);
}


int CppSQLite3DB::execDML(const char* szSQL)
{
	checkDB();

	char* szError=0;

	int nRet = sqlite3_exec(mpDB, szSQL, 0, 0, &szError);

	if (nRet == SQLITE_OK)
	{
		return sqlite3_changes(mpDB);
	}
	else
	{
		throw CppSQLite3Exception(nRet, szError);
	}
}


CppSQLite3Query CppSQLite3DB::execQuery(const char* szSQL)
{
	checkDB();

	sqlite3_stmt* pVM = compile(szSQL);

	int nRet = sqlite3_step(pVM);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLite3Query(mpDB, pVM, true/*eof*/);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLite3Query(mpDB, pVM, false/*eof*/);
	}
	else
	{
		nRet = sqlite3_finalize(pVM);
		const char* szError= sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet, (char*)szError, DONT_DELETE_MSG);
	}
}


int CppSQLite3DB::execScalar(const char* szSQL, int nNullValue/*=0*/)
{
	CppSQLite3Query q = execQuery(szSQL);

	if (q.eof() || q.numFields() < 1)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Invalid scalar query",
								DONT_DELETE_MSG);
	}

	return q.getIntField(0, nNullValue);
}


CppSQLite3Table CppSQLite3DB::getTable(const char* szSQL)
{
	checkDB();

	char* szError=0;
	char** paszResults=0;
	int nRet;
	int nRows(0);
	int nCols(0);

	nRet = sqlite3_get_table(mpDB, szSQL, &paszResults, &nRows, &nCols, &szError);

	if (nRet == SQLITE_OK)
	{
		return CppSQLite3Table(paszResults, nRows, nCols);
	}
	else
	{
		throw CppSQLite3Exception(nRet, szError);
	}
}


sqlite_int64 CppSQLite3DB::lastRowId()
{
	return sqlite3_last_insert_rowid(mpDB);
}


void CppSQLite3DB::setBusyTimeout(int nMillisecs)
{
	mnBusyTimeoutMs = nMillisecs;
	sqlite3_busy_timeout(mpDB, mnBusyTimeoutMs);
}


void CppSQLite3DB::checkDB()
{
	if (!mpDB)
	{
		throw CppSQLite3Exception(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


sqlite3_stmt* CppSQLite3DB::compile(const char* szSQL)
{
	checkDB();

	const char* szTail=0;
	sqlite3_stmt* pVM;

	int nRet = sqlite3_prepare_v2(mpDB, szSQL, -1, &pVM, &szTail);

	if (nRet != SQLITE_OK)
	{
		const char* szError = sqlite3_errmsg(mpDB);
		throw CppSQLite3Exception(nRet,
								(char*)szError,
								DONT_DELETE_MSG);
	}

	return pVM;
}

bool CppSQLite3DB::IsAutoCommitOn()
{
	checkDB();
	return sqlite3_get_autocommit(mpDB) ? true : false;
}


// SQLite encode.c reproduced here, containing implementation notes and source
// for sqlite3_encode_binary() and sqlite3_decode_binary() 


/*
** 2002 April 25
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains helper routines used to translate binary data into
** a null-terminated string (suitable for use in SQLite) and back again.
** These are convenience routines for use by people who want to store binary
** data in an SQLite database.  The code in this file is not used by any other
** part of the SQLite library.
**
** $Id: encode.c,v 1.10 2004/01/14 21:59:23 drh Exp $
*/

/*
** How This Encoder Works
**
** The output is allowed to contain any character except 0x27 (') and
** 0x00.  This is accomplished by using an escape character to encode
** 0x27 and 0x00 as a two-byte sequence.  The escape character is always
** 0x01.  An 0x00 is encoded as the two byte sequence 0x01 0x01.  The
** 0x27 character is encoded as the two byte sequence 0x01 0x03.  Finally,
** the escape character itself is encoded as the two-character sequence
** 0x01 0x02.
**
** To summarize, the encoder works by using an escape sequences as follows:
**
**       0x00  ->  0x01 0x01
**       0x01  ->  0x01 0x02
**       0x27  ->  0x01 0x03
**
** If that were all the encoder did, it would work, but in certain cases
** it could double the size of the encoded string.  For example, to
** encode a string of 100 0x27 characters would require 100 instances of
** the 0x01 0x03 escape sequence resulting in a 200-character output.
** We would prefer to keep the size of the encoded string smaller than
** this.
**
** To minimize the encoding size, we first add a fixed offset value to each 
** byte in the sequence.  The addition is modulo 256.  (That is to say, if
** the sum of the original character value and the offset exceeds 256, then
** the higher order bits are truncated.)  The offset is chosen to minimize
** the number of characters in the string that need to be escaped.  For
** example, in the case above where the string was composed of 100 0x27
** characters, the offset might be 0x01.  Each of the 0x27 characters would
** then be converted into an 0x28 character which would not need to be
** escaped at all and so the 100 character input string would be converted
** into just 100 characters of output.  Actually 101 characters of output - 
** we have to record the offset used as the first byte in the sequence so
** that the string can be decoded.  Since the offset value is stored as
** part of the output string and the output string is not allowed to contain
** characters 0x00 or 0x27, the offset cannot be 0x00 or 0x27.
**
** Here, then, are the encoding steps:
**
**     (1)   Choose an offset value and make it the first character of
**           output.
**
**     (2)   Copy each input character into the output buffer, one by
**           one, adding the offset value as you copy.
**
**     (3)   If the value of an input character plus offset is 0x00, replace
**           that one character by the two-character sequence 0x01 0x01.
**           If the sum is 0x01, replace it with 0x01 0x02.  If the sum
**           is 0x27, replace it with 0x01 0x03.
**
**     (4)   Put a 0x00 terminator at the end of the output.
**
** Decoding is obvious:
**
**     (5)   Copy encoded characters except the first into the decode 
**           buffer.  Set the first encoded character aside for use as
**           the offset in step 7 below.
**
**     (6)   Convert each 0x01 0x01 sequence into a single character 0x00.
**           Convert 0x01 0x02 into 0x01.  Convert 0x01 0x03 into 0x27.
**
**     (7)   Subtract the offset value that was the first character of
**           the encoded buffer from all characters in the output buffer.
**
** The only tricky part is step (1) - how to compute an offset value to
** minimize the size of the output buffer.  This is accomplished by testing
** all offset values and picking the one that results in the fewest number
** of escapes.  To do that, we first scan the entire input and count the
** number of occurances of each character value in the input.  Suppose
** the number of 0x00 characters is N(0), the number of occurances of 0x01
** is N(1), and so forth up to the number of occurances of 0xff is N(255).
** An offset of 0 is not allowed so we don't have to test it.  The number
** of escapes required for an offset of 1 is N(1)+N(2)+N(40).  The number
** of escapes required for an offset of 2 is N(2)+N(3)+N(41).  And so forth.
** In this way we find the offset that gives the minimum number of escapes,
** and thus minimizes the length of the output string.
*/

/*
** Encode a binary buffer "in" of size n bytes so that it contains
** no instances of characters '\'' or '\000'.  The output is 
** null-terminated and can be used as a string value in an INSERT
** or UPDATE statement.  Use sqlite3_decode_binary() to convert the
** string back into its original binary.
**
** The result is written into a preallocated output buffer "out".
** "out" must be able to hold at least 2 +(257*n)/254 bytes.
** In other words, the output will be expanded by as much as 3
** bytes for every 254 bytes of input plus 2 bytes of fixed overhead.
** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.)
**
** The return value is the number of characters in the encoded
** string, excluding the "\000" terminator.
*/
int sqlite3_encode_binary(const unsigned char *in, int n, unsigned char *out){
  int i, j, e, m;
  int cnt[256];
  if( n<=0 ){
    out[0] = 'x';
    out[1] = 0;
    return 1;
  }
  memset(cnt, 0, sizeof(cnt));
  for(i=n-1; i>=0; i--){ cnt[in[i]]++; }
  m = n;
  for(i=1; i<256; i++){
    int sum;
    if( i=='\'' ) continue;
    sum = cnt[i] + cnt[(i+1)&0xff] + cnt[(i+'\'')&0xff];
    if( sum<m ){
      m = sum;
      e = i;
      if( m==0 ) break;
    }
  }
  out[0] = e;
  j = 1;
  for(i=0; i<n; i++){
    int c = (in[i] - e)&0xff;
    if( c==0 ){
      out[j++] = 1;
      out[j++] = 1;
    }else if( c==1 ){
      out[j++] = 1;
      out[j++] = 2;
    }else if( c=='\'' ){
      out[j++] = 1;
      out[j++] = 3;
    }else{
      out[j++] = c;
    }
  }
  out[j] = 0;
  return j;
}

/*
** Decode the string "in" into binary data and write it into "out".
** This routine reverses the encoding created by sqlite3_encode_binary().
** The output will always be a few bytes less than the input.  The number
** of bytes of output is returned.  If the input is not a well-formed
** encoding, -1 is returned.
**
** The "in" and "out" parameters may point to the same buffer in order
** to decode a string in place.
*/
int sqlite3_decode_binary(const unsigned char *in, unsigned char *out){
  int i, c, e;
  e = *(in++);
  i = 0;
  while( (c = *(in++))!=0 ){
    if( c==1 ){
      c = *(in++);
      if( c==1 ){
        c = 0;
      }else if( c==2 ){
        c = 1;
      }else if( c==3 ){
        c = '\'';
      }else{
        return -1;
      }
    }
    out[i++] = (c + e)&0xff;
  }
  return i;
}

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