学习iPhone开发中 sqlite3的

$ sqlite3 foo.db

create table film(title, length, year, starring);

create table table_name(field1, field2, field3, ...);

create index film_title_index on film(title);

create index index_name on table_name(field_to_be_indexed);

insert into table_name values(data1, data2, data3, ...);

insert into film values ('Silence of the Lambs, The', 118, 1991, 'Jodie Foster');insert into film values ('Contact', 153, 1997, 'Jodie Foster');insert into film values ('Crouching Tiger, Hidden Dragon', 120, 2000, 'Yun-Fat Chow');insert into film values ('Hours, The', 114, 2002, 'Nicole Kidman');

select columns from table_name where expression;

select * from film;

select * from film limit 10;

select * from film order by year limit 10;

select * from film order by year desc limit 10;

select title, year from film order by year desc limit 10;

select * from film where starring='Jodie Foster';

select * from film where starring like 'Jodie%';

select title, year from film where starring like 'Jodie%' and year >= 1985 order by year desc limit 10;

select count(*) from film;

select count(*) from film where year >= 1985;

update film set starring='Jodie Foster' where starring='Jodee Foster';

delete from film where year < 1970;

sqlite3 film.db "select * from film;"

sqlite3 -html film.db "select * from film;"

sqlite3 film.db ".dump" > output.sql

sqlite3 film.db < output.sql

sqlite3* database_;
-(BOOL) open{
       NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"mydb.sql"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL find = [fileManager fileExistsAtPath:path];
    //找到数据库文件mydb.sql
    if (find) {
        NSLog(@"Database file have already existed.");
        if(sqlite3_open([path UTF8String], &database_) != SQLITE_OK) {
            sqlite3_close(database_);
            NSLog(@"Error: open database file.");
            return NO;
        }
        return YES;
    }
    if(sqlite3_open([path UTF8String], &database_) == SQLITE_OK) {
        bFirstCreate_ = YES;
        [self createChannelsTable:database_];//在后面实现函数createChannelsTable
        return YES;
    } else {
        sqlite3_close(database_);
        NSLog(@"Error: open database file.");
        return NO;
    }
    return NO;
}

//创建表格，假设有五个字段，（id，cid，title，p_w_picpathData ，p_w_picpathLen ）
//说明一下，id为表格的主键，必须有。
//cid，和title都是字符串，p_w_picpathData是二进制数据，p_w_picpathLen 是该二进制数据的长度。
- (BOOL) createChannelsTable:(sqlite3*)db{
    char *sql = "CREATE TABLE channels (id integer primary key, \
                                        cid text, \
                                        title text, \
                                        p_w_picpathData BLOB, \
                                        p_w_picpathLen integer)";
    sqlite3_stmt *statement;
    if(sqlite3_prepare_v2(db, sql, -1, &statement, nil) != SQLITE_OK) {
        NSLog(@"Error: failed to prepare statement:create channels table");
        return NO;
    }
    int success = sqlite3_step(statement);
    sqlite3_finalize(statement);
    if ( success != SQLITE_DONE) {
        NSLog(@"Error: failed to dehydrate:CREATE TABLE channels");
        return NO;
    }
    NSLog(@"Create table 'channels' successed.");
    return YES;
}

- (BOOL) insertOneChannel:(Channel*)channel{
    NSData* ImageData = UIImagePNGRepresentation( channel.p_w_picpath_);
    NSInteger Imagelen = [ImageData length];
    sqlite3_stmt *statement;
    static char *sql = "INSERT INTO channels (cid,title,p_w_picpathData,p_w_picpathLen)\
                        VALUES(?,?,?,?)";
    //问号的个数要和(cid,title,p_w_picpathData,p_w_picpathLen)里面字段的个数匹配，代表未知的值，将在下面将值和字段关联。
    int success = sqlite3_prepare_v2(database_, sql, -1, &statement, NULL);
    if (success != SQLITE_OK) {
        NSLog(@"Error: failed to insert:channels");
        return NO;
    }
 
   //这里的数字1，2，3，4代表第几个问号
    sqlite3_bind_text(statement, 1, [channel.id_ UTF8String], -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(statement, 2, [channel.title_ UTF8String], -1, SQLITE_TRANSIENT);
    sqlite3_bind_blob(statement, 3, [ImageData bytes], Imagelen, SQLITE_TRANSIENT);
    sqlite3_bind_int(statement, 4, Imagelen);    

    success = sqlite3_step(statement);
    sqlite3_finalize(statement);
 
    if (success == SQLITE_ERROR) {
        NSLog(@"Error: failed to insert into the database with message.");
        return NO;
    } 
 
  NSLog(@"Insert One Channel#############:id = %@",channel.id_);
    return YES;
}

- (void) getChannels:(NSMutableArray*)fChannels{
    sqlite3_stmt *statement = nil;
    char *sql = "SELECT * FROM channels";
    if (sqlite3_prepare_v2(database_, sql, -1, &statement, NULL) != SQLITE_OK) {
        NSLog(@"Error: failed to prepare statement with message:get channels.");
    }
    //查询结果集中一条一条的遍历所有的记录，这里的数字对应的是列值。
    while (sqlite3_step(statement) == SQLITE_ROW) {
        char* cid       = (char*)sqlite3_column_text(statement, 1);
        char* title     = (char*)sqlite3_column_text(statement, 2);
        Byte* p_w_picpathData = (Byte*)sqlite3_column_blob(statement, 3);
        int p_w_picpathLen    = sqlite3_column_int(statement, 4);        
        Channel* channel = [[Channel alloc] init];
        if(cid)
            channel.id_ = [NSString stringWithUTF8String:cid];
        if(title)
            channel.title_ = [NSString stringWithUTF8String:title];
        if(p_w_picpathData){
            UIImage* p_w_picpath = [UIImage p_w_picpathWithData:[NSData dataWithBytes:p_w_picpathData length:p_w_picpathLen]];
            channel.p_w_picpath_ = p_w_picpath;
        }
         [fChannels addObject:channel];
        [channel release];
    }
    sqlite3_finalize(statement);
}
 iphone访问本地数据库sqlite3

// 首先获取iPhone上Sqlite3的数据库文件的地址 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
NSString *documentsDirectory = [paths objectAtIndex:0];  
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"database_name"];  
// 打开Sqlite3的数据库文件 
sqlite3 *database;  
sqlite3_open([path UTF8String], &database);  
// 定义SQL文 
sqlite3_stmt *stmt;  
const char *sql = "SELECT * FROM table_name WHERE pk=? and name=?";  
sqlite3_prepare_v2(database, sql, -1, &stmt, NULL);  
// 邦定第一个int参数 
sqlite3_bind_int(stmt, 1, 1);  
// 邦定第二个字符串参数 
sqlite3_bind_text(stmt, 2, [title UTF8String], -1, SQLITE_TRANSIENT);  
// 执行SQL文，并获取结果 
sqlite3_step(stmt);  
// 释放资源 
sqlite3_finalize(stmt);  
// 关闭Sqlite3数据库 
sqlite3_close(database);