ADO.NET FOR MySQL帮助类

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using MySql.Data.MySqlClient;
using System.Configuration;
using System.Data.Common;
using System.Collections.Generic;

/// <summary>
/// 数据访问抽象基础类
/// Copyright (C) Maticsoft
/// </summary>
public abstract class DbHelperMySQL
{
    //数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.
    public static string connectionString =
        System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();

    public DbHelperMySQL()
    {
    }

    #region 公用方法

    /// <summary>
    /// 得到最大值
    /// </summary>
    /// <param name="FieldName"></param>
    /// <param name="TableName"></param>
    /// <returns></returns>
    public static int GetMaxID(string FieldName, string TableName)
    {
        string strsql = "select max(" + FieldName + ")+1 from " + TableName;
        object obj = GetSingle(strsql);
        if (obj == null)
        {
            return 1;
        }
        else
        {
            return int.Parse(obj.ToString());
        }
    }

    /// <summary>
    /// 是否存在
    /// </summary>
    /// <param name="strSql"></param>
    /// <returns></returns>
    public static bool Exists(string strSql)
    {
        object obj = GetSingle(strSql);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    /// <summary>
    /// 是否存在（基于MySqlParameter）
    /// </summary>
    /// <param name="strSql"></param>
    /// <param name="cmdParms"></param>
    /// <returns></returns>
    public static bool Exists(string strSql, params MySqlParameter[] cmdParms)
    {
        object obj = GetSingle(strSql, cmdParms);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    #endregion

    #region  执行简单SQL语句

    /// <summary>
    /// 执行SQL语句，返回影响的记录数
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    connection.Close();
                    throw e;
                }
            }
        }
    }

    public static int ExecuteSqlByTime(string SQLString, int Times)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    cmd.CommandTimeout = Times;
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    connection.Close();
                    throw e;
                }
            }
        }
    }

    /// <summary>
    /// 执行带一个存储过程参数的的SQL语句。
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString, string content)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            MySqlCommand cmd = new MySqlCommand(SQLString, connection);
            MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content",
                SqlDbType.NText);
            myParameter.Value = content;
            cmd.Parameters.Add(myParameter);
            try
            {
                connection.Open();
                int rows = cmd.ExecuteNonQuery();
                return rows;
            }
            catch (MySql.Data.MySqlClient.MySqlException e)
            {
                throw e;
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
    }

    /// <summary>
    /// 执行带一个存储过程参数的的SQL语句。
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
    /// <returns>影响的记录数</returns>
    public static object ExecuteSqlGet(string SQLString, string content)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            MySqlCommand cmd = new MySqlCommand(SQLString, connection);
            MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content",
                SqlDbType.NText);
            myParameter.Value = content;
            cmd.Parameters.Add(myParameter);
            try
            {
                connection.Open();
                object obj = cmd.ExecuteScalar();
                if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                {
                    return null;
                }
                else
                {
                    return obj;
                }
            }
            catch (MySql.Data.MySqlClient.MySqlException e)
            {
                throw e;
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
    }

    /// <summary>
    /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
    /// </summary>
    /// <param name="strSQL">SQL语句</param>
    /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            MySqlCommand cmd = new MySqlCommand(strSQL, connection);
            MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@fs",
                SqlDbType.Image);
            myParameter.Value = fs;
            cmd.Parameters.Add(myParameter);
            try
            {
                connection.Open();
                int rows = cmd.ExecuteNonQuery();
                return rows;
            }
            catch (MySql.Data.MySqlClient.MySqlException e)
            {
                throw e;
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
    }

    /// <summary>
    /// 执行一条计算查询结果语句，返回查询结果（object）。
    /// </summary>
    /// <param name="SQLString">计算查询结果语句</param>
    /// <returns>查询结果（object）</returns>
    public static object GetSingle(string SQLString)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    object obj = cmd.ExecuteScalar();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    connection.Close();
                    throw e;
                }
            }
        }
    }

    public static object GetSingle(string SQLString, int Times)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    cmd.CommandTimeout = Times;
                    object obj = cmd.ExecuteScalar();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    connection.Close();
                    throw e;
                }
            }
        }
    }

    /// <summary>
    /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader进行Close )
    /// </summary>
    /// <param name="strSQL">查询语句</param>
    /// <returns>MySqlDataReader</returns>
    public static MySqlDataReader ExecuteReader(string strSQL)
    {
        MySqlConnection connection = new MySqlConnection(connectionString);
        MySqlCommand cmd = new MySqlCommand(strSQL, connection);
        try
        {
            connection.Open();
            MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            return myReader;
        }
        catch (MySql.Data.MySqlClient.MySqlException e)
        {
            throw e;
        }

    }

    /// <summary>
    /// 执行查询语句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查询语句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            DataSet ds = new DataSet();
            try
            {
                connection.Open();
                MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
                command.Fill(ds, "ds");
            }
            catch (MySql.Data.MySqlClient.MySqlException ex)
            {
                throw new Exception(ex.Message);
            }
            return ds;
        }
    }

    public static DataSet Query(string SQLString, int Times)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            DataSet ds = new DataSet();
            try
            {
                connection.Open();
                MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
                command.SelectCommand.CommandTimeout = Times;
                command.Fill(ds, "ds");
            }
            catch (MySql.Data.MySqlClient.MySqlException ex)
            {
                throw new Exception(ex.Message);
            }
            return ds;
        }
    }

    #endregion

    #region 执行带参数的SQL语句

    /// <summary>
    /// 执行SQL语句，返回影响的记录数
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString, params MySqlParameter[] cmdParms)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand())
            {
                try
                {
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                    int rows = cmd.ExecuteNonQuery();
                    cmd.Parameters.Clear();
                    return rows;
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    throw e;
                }
            }
        }
    }

    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
    public static void ExecuteSqlTran(Hashtable SQLStringList)
    {
        using (MySqlConnection conn = new MySqlConnection(connectionString))
        {
            conn.Open();
            using (MySqlTransaction trans = conn.BeginTransaction())
            {
                MySqlCommand cmd = new MySqlCommand();
                try
                {
                    //循环
                    foreach (DictionaryEntry myDE in SQLStringList)
                    {
                        string cmdText = myDE.Key.ToString();
                        MySqlParameter[] cmdParms = (MySqlParameter[]) myDE.Value;
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                        int val = cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();
                    }
                    trans.Commit();
                }
                catch
                {
                    trans.Rollback();
                    throw;
                }
            }
        }
    }

    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
    public static int ExecuteSqlTran(System.Collections.Generic.List<CommandInfo> cmdList)
    {
        using (MySqlConnection conn = new MySqlConnection(connectionString))
        {
            conn.Open();
            using (MySqlTransaction trans = conn.BeginTransaction())
            {
                MySqlCommand cmd = new MySqlCommand();
                try
                {
                    int count = 0;
                    //循环
                    foreach (CommandInfo myDE in cmdList)
                    {
                        string cmdText = myDE.CommandText;
                        MySqlParameter[] cmdParms = (MySqlParameter[]) myDE.Parameters;
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);

                        if (myDE.EffentNextType == EffentNextType.WhenHaveContine ||
                            myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
                        {
                            if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
                            {
                                trans.Rollback();
                                return 0;
                            }

                            object obj = cmd.ExecuteScalar();
                            bool isHave = false;
                            if (obj == null && obj == DBNull.Value)
                            {
                                isHave = false;
                            }
                            isHave = Convert.ToInt32(obj) > 0;

                            if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
                            {
                                trans.Rollback();
                                return 0;
                            }
                            if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
                            {
                                trans.Rollback();
                                return 0;
                            }
                            continue;
                        }
                        int val = cmd.ExecuteNonQuery();
                        count += val;
                        if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
                        {
                            trans.Rollback();
                            return 0;
                        }
                        cmd.Parameters.Clear();
                    }
                    trans.Commit();
                    return count;
                }
                catch
                {
                    trans.Rollback();
                    throw;
                }
            }
        }
    }

    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
    public static void ExecuteSqlTranWithIndentity(System.Collections.Generic.List<CommandInfo> SQLStringList)
    {
        using (MySqlConnection conn = new MySqlConnection(connectionString))
        {
            conn.Open();
            using (MySqlTransaction trans = conn.BeginTransaction())
            {
                MySqlCommand cmd = new MySqlCommand();
                try
                {
                    int indentity = 0;
                    //循环
                    foreach (CommandInfo myDE in SQLStringList)
                    {
                        string cmdText = myDE.CommandText;
                        MySqlParameter[] cmdParms = (MySqlParameter[]) myDE.Parameters;
                        foreach (MySqlParameter q in cmdParms)
                        {
                            if (q.Direction == ParameterDirection.InputOutput)
                            {
                                q.Value = indentity;
                            }
                        }
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                        int val = cmd.ExecuteNonQuery();
                        foreach (MySqlParameter q in cmdParms)
                        {
                            if (q.Direction == ParameterDirection.Output)
                            {
                                indentity = Convert.ToInt32(q.Value);
                            }
                        }
                        cmd.Parameters.Clear();
                    }
                    trans.Commit();
                }
                catch
                {
                    trans.Rollback();
                    throw;
                }
            }
        }
    }

    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
    public static void ExecuteSqlTranWithIndentity(Hashtable SQLStringList)
    {
        using (MySqlConnection conn = new MySqlConnection(connectionString))
        {
            conn.Open();
            using (MySqlTransaction trans = conn.BeginTransaction())
            {
                MySqlCommand cmd = new MySqlCommand();
                try
                {
                    int indentity = 0;
                    //循环
                    foreach (DictionaryEntry myDE in SQLStringList)
                    {
                        string cmdText = myDE.Key.ToString();
                        MySqlParameter[] cmdParms = (MySqlParameter[]) myDE.Value;
                        foreach (MySqlParameter q in cmdParms)
                        {
                            if (q.Direction == ParameterDirection.InputOutput)
                            {
                                q.Value = indentity;
                            }
                        }
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                        int val = cmd.ExecuteNonQuery();
                        foreach (MySqlParameter q in cmdParms)
                        {
                            if (q.Direction == ParameterDirection.Output)
                            {
                                indentity = Convert.ToInt32(q.Value);
                            }
                        }
                        cmd.Parameters.Clear();
                    }
                    trans.Commit();
                }
                catch
                {
                    trans.Rollback();
                    throw;
                }
            }
        }
    }

    /// <summary>
    /// 执行一条计算查询结果语句，返回查询结果（object）。
    /// </summary>
    /// <param name="SQLString">计算查询结果语句</param>
    /// <returns>查询结果（object）</returns>
    public static object GetSingle(string SQLString, params MySqlParameter[] cmdParms)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            using (MySqlCommand cmd = new MySqlCommand())
            {
                try
                {
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                    object obj = cmd.ExecuteScalar();
                    cmd.Parameters.Clear();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (MySql.Data.MySqlClient.MySqlException e)
                {
                    throw e;
                }
            }
        }
    }

    /// <summary>
    /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader进行Close )
    /// </summary>
    /// <param name="strSQL">查询语句</param>
    /// <returns>MySqlDataReader</returns>
    public static MySqlDataReader ExecuteReader(string SQLString, params MySqlParameter[] cmdParms)
    {
        MySqlConnection connection = new MySqlConnection(connectionString);
        MySqlCommand cmd = new MySqlCommand();
        try
        {
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            cmd.Parameters.Clear();
            return myReader;
        }
        catch (MySql.Data.MySqlClient.MySqlException e)
        {
            throw e;
        }
        //			finally
        //			{
        //				cmd.Dispose();
        //				connection.Close();
        //			}	

    }

    /// <summary>
    /// 执行查询语句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查询语句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString, params MySqlParameter[] cmdParms)
    {
        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            MySqlCommand cmd = new MySqlCommand();
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            using (MySqlDataAdapter da = new MySqlDataAdapter(cmd))
            {
                DataSet ds = new DataSet();
                try
                {
                    da.Fill(ds, "ds");
                    cmd.Parameters.Clear();
                }
                catch (MySql.Data.MySqlClient.MySqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }
    }

    private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, string cmdText,
        MySqlParameter[] cmdParms)
    {
        if (conn.State != ConnectionState.Open)
            conn.Open();
        cmd.Connection = conn;
        cmd.CommandText = cmdText;
        if (trans != null)
            cmd.Transaction = trans;
        cmd.CommandType = CommandType.Text; //cmdType;
        if (cmdParms != null)
        {
            foreach (MySqlParameter parameter in cmdParms)
            {
                if ((parameter.Direction == ParameterDirection.InputOutput ||
                     parameter.Direction == ParameterDirection.Input) &&
                    (parameter.Value == null))
                {
                    parameter.Value = DBNull.Value;
                }
                cmd.Parameters.Add(parameter);
            }
        }
    }

    #endregion

}