封装了 System.Data.SQLite 的数据库助手类

using System;
using System.Data;
using System.Data.Common;
using System.Data.SQLite;
namespace SQLiteQueryBrowser
{
    /// <summary>
    /// 说明：这是一个针对System.Data.SQLite的数据库常规操作封装的通用类。
    /// Version:0.1
    /// </summary>
    public class SQLiteDBHelper
    {
        private string connectionString = string.Empty;
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="dbPath">SQLite数据库文件路径</param>
        public SQLiteDBHelper(string dbPath)
        {
            this.connectionString = "Data Source=" + dbPath;
        }
        /// <summary>
        /// 创建SQLite数据库文件
        /// </summary>
        /// <param name="dbPath">要创建的SQLite数据库文件路径</param>
        public static void CreateDB(string dbPath)
        {
            using (SQLiteConnection connection = new SQLiteConnection("Data Source=" + dbPath))
            {
                connection.Open();
                using (SQLiteCommand command = new SQLiteCommand(connection))
                {
                    command.CommandText = "CREATE TABLE Demo(id integer NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE)";
                    command.ExecuteNonQuery();

                command.CommandText = "DROP TABLE Demo";
                command.ExecuteNonQuery();
            }
        }
    }
    /// <summary>
    /// 对SQLite数据库执行增删改操作，返回受影响的行数。
    /// </summary>
    /// <param name="sql">要执行的增删改的SQL语句</param>
    /// <param name="parameters">执行增删改语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
    /// <returns></returns>
    public int ExecuteNonQuery(string sql, SQLiteParameter[] parameters)
    {
        int affectedRows = 0;
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            connection.Open();
            using (DbTransaction transaction = connection.BeginTransaction())
            {
                using (SQLiteCommand command = new SQLiteCommand(connection))
                {
                    command.CommandText = sql;
                    if (parameters != null)
                    {
                        command.Parameters.AddRange(parameters);
                    }
                    affectedRows = command.ExecuteNonQuery();
                }
                transaction.Commit();
            }
        }
        return affectedRows;
    }
    /// <summary>
    /// 执行一个查询语句，返回一个关联的SQLiteDataReader实例
    /// </summary>
    /// <param name="sql">要执行的查询语句</param>
    /// <param name="parameters">执行SQL查询语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
    /// <returns></returns>
    public SQLiteDataReader ExecuteReader(string sql, SQLiteParameter[] parameters)
    {
        SQLiteConnection connection = new SQLiteConnection(connectionString);
        SQLiteCommand command = new SQLiteCommand(sql, connection);
        if (parameters != null)
        {
            command.Parameters.AddRange(parameters);
        }
        connection.Open();
        return command.ExecuteReader(CommandBehavior.CloseConnection);
    }
    /// <summary>
    /// 执行一个查询语句，返回一个包含查询结果的DataTable
    /// </summary>
    /// <param name="sql">要执行的查询语句</param>
    /// <param name="parameters">执行SQL查询语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
    /// <returns></returns>
    public DataTable ExecuteDataTable(string sql, SQLiteParameter[] parameters)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand command = new SQLiteCommand(sql, connection))
            {
                if (parameters != null)
                {
                    command.Parameters.AddRange(parameters);
                }
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(command);
                DataTable data = new DataTable();
                adapter.Fill(data);
                return data;
            }
        }

    }
    /// <summary>
    /// 执行一个查询语句，返回查询结果的第一行第一列
    /// </summary>
    /// <param name="sql">要执行的查询语句</param>
    /// <param name="parameters">执行SQL查询语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
    /// <returns></returns>
    public Object ExecuteScalar(string sql, SQLiteParameter[] parameters)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand command = new SQLiteCommand(sql, connection))
            {
                if (parameters != null)
                {
                    command.Parameters.AddRange(parameters);
                }
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(command);
                DataTable data = new DataTable();
                adapter.Fill(data);
                return data;
            }
        }
    }
    /// <summary>
    /// 查询数据库中的所有数据类型信息
    /// </summary>
    /// <returns></returns>
    public DataTable GetSchema()
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            connection.Open();
            DataTable data=connection.GetSchema("TABLES");
            connection.Close();
            //foreach (DataColumn column in data.Columns)
            //{
            //    Console.WriteLine(column.ColumnName);
            //}
            return data;
        }
    }

}

}
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