在.NET连接MySQL以及封装好的MySQLHelper.cs

1、首先上MySQL网站下驱动：http://www.mysql.com/products/connector/

2、安装下载的安装包

3、我们在Visual Studio里创建一个Web Application，然后引入X:\XXXX\MySQL\MySQL Connector Net 6.3.6\Assemblies下的v2.0或v4.0里的DLL文件。

在MySQLHelper里面加入：

using MySql.Data.MySqlClient;

在Web.config里面加入MySQL数据库的连接字符串：

<connectionStrings>
<add name="MySqlStr" connectionString="server = localhost; user id = XXXX; password = XXXX; database = XXXX"/>
</connectionStrings>

4、封装好的MySQLHelper类

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

namespace DBUtility
{
    /// <summary>
    /// The SQLHelper class is intended to encapsulate high performance,
    /// scalable best practices for common uses of SqlClient.
    /// </summary>
    public abstract class MySQLHelper
    {
        // Read the connection strings from the configuration file
        public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.ConnectionStrings["OraConnString1"].ConnectionString;
        public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.ConnectionStrings["OraConnString2"].ConnectionString;
        public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.ConnectionStrings["OraConnString3"].ConnectionString;
        public static readonly string ConnectionStringProfile = ConfigurationManager.ConnectionStrings["OraProfileConnString"].ConnectionString;
        public static readonly string ConnectionStringMembership = ConfigurationManager.ConnectionStrings["OraMembershipConnString"].ConnectionString;

        //Create a hashtable for the parameter cached
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        /// <summary>
        /// Execute a database query which does not include a select
        /// </summary>
        /// <param name="connString">Connection string to database</param>
        /// <param name="cmdType">Command type either stored procedure or SQL</param>
        /// <param name="cmdText">Acutall SQL Command</param>
        /// <param name="commandParameters">Parameters to bind to the command</param>
        /// <returns></returns>
        public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {
            // Create a new MySql command
            MySqlCommand cmd = new MySqlCommand();

            //Create a connection
            using (MySqlConnection connection = new MySqlConnection(connectionString))
            {

                //Prepare the command
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);

                //Execute the command
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        /// Execute an MySqlCommand (that returns no resultset) against an existing database transaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter(":prodid", 24));
        /// </remarks>
        /// <param name="trans">an existing database transaction</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of MySqlParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(MySqlTransaction trans, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {
            MySqlCommand cmd = new MySqlCommand();
            PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        /// <summary>
        /// Execute an MySqlCommand (that returns no resultset) against an existing database connection
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter(":prodid", 24));
        /// </remarks>
        /// <param name="conn">an existing database connection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of MySqlParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(MySqlConnection connection, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {

            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        /// <summary>
        /// Execute a select query that will return a result set
        /// </summary>
        /// <param name="connString">Connection string</param>
        //// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of MySqlParamters used to execute the command</param>
        /// <returns></returns>
        public static MySqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {

            //Create the command and connection
            MySqlCommand cmd = new MySqlCommand();
            MySqlConnection conn = new MySqlConnection(connectionString);

            try
            {
                //Prepare the command to execute
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

                //Execute the query, stating that the connection should close when the resulting datareader has been read
                MySqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;

            }
            catch
            {

                //If an error occurs close the connection as the reader will not be used and we expect it to close the connection
                conn.Close();
                throw;
            }
        }

        /// <summary>
        /// Execute an MySqlCommand that returns the first column of the first record against the database specified in the connection string
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter(":prodid", 24));
        /// </remarks>
        /// <param name="connectionString">a valid connection string for a SqlConnection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of MySqlParamters used to execute the command</param>
        /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
        public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {
            MySqlCommand cmd = new MySqlCommand();

            using (MySqlConnection conn = new MySqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }
        }

        ///     <summary>
        ///     Execute a MySqlCommand (that returns a 1x1 resultset)   against the     specified SqlTransaction
        ///     using the provided parameters.
        ///     </summary>
        ///     <param name="transaction">A     valid SqlTransaction</param>
        ///     <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        ///     <param name="commandText">The stored procedure name     or PL/SQL command</param>
        ///     <param name="commandParameters">An array of     MySqlParamters used to execute the command</param>
        ///     <returns>An     object containing the value     in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
        {
            if (transaction == null)
                throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null)
                throw new ArgumentException("The transaction was rollbacked     or commited, please     provide an open transaction.", "transaction");

            // Create a command and     prepare it for execution
            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

            // Execute the command & return     the     results
            object retval = cmd.ExecuteScalar();

            // Detach the SqlParameters from the command object, so     they can be     used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// <summary>
        /// Execute an MySqlCommand that returns the first column of the first record against an existing database connection
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:
        ///  Object obj = ExecuteScalar(conn, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter(":prodid", 24));
        /// </remarks>
        /// <param name="conn">an existing database connection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of MySqlParamters used to execute the command</param>
        /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
        public static object ExecuteScalar(MySqlConnection connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {
            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(cmd, connectionString, null, cmdType, cmdText, commandParameters);
            object val = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            return val;
        }

        /// <summary>
        /// Add a set of parameters to the cached
        /// </summary>
        /// <param name="cacheKey">Key value to look up the parameters</param>
        /// <param name="commandParameters">Actual parameters to cached</param>
        public static void CacheParameters(string cacheKey, params MySqlParameter[] commandParameters)
        {
            parmCache[cacheKey] = commandParameters;
        }

        /// <summary>
        /// Fetch parameters from the cache
        /// </summary>
        /// <param name="cacheKey">Key to look up the parameters</param>
        /// <returns></returns>
        public static MySqlParameter[] GetCachedParameters(string cacheKey)
        {
            MySqlParameter[] cachedParms = (MySqlParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            // If the parameters are in the cache
            MySqlParameter[] clonedParms = new MySqlParameter[cachedParms.Length];

            // return a copy of the parameters
            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (MySqlParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        /// <summary>
        /// Internal function to prepare a command for execution by the database
        /// </summary>
        /// <param name="cmd">Existing command object</param>
        /// <param name="conn">Database connection object</param>
        /// <param name="trans">Optional transaction object</param>
        /// <param name="cmdType">Command type, e.g. stored procedure</param>
        /// <param name="cmdText">Command test</param>
        /// <param name="commandParameters">Parameters for the command</param>
        private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, CommandType cmdType, string cmdText, MySqlParameter[] commandParameters)
        {

            //Open the connection if required
            if (conn.State != ConnectionState.Open)
                conn.Open();

            //Set up the command
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            cmd.CommandType = cmdType;

            //Bind it to the transaction if it exists
            if (trans != null)
                cmd.Transaction = trans;

            // Bind the parameters passed in
            if (commandParameters != null)
            {
                foreach (MySqlParameter parm in commandParameters)
                    cmd.Parameters.Add(parm);
            }
        }

        /// <summary>
        /// Converter to use boolean data type with MySql
        /// </summary>
        /// <param name="value">Value to convert</param>
        /// <returns></returns>
        public static string MySqlBit(bool value)
        {
            if (value)
                return "Y";
            else
                return "N";
        }

        /// <summary>
        /// Converter to use boolean data type with MySql
        /// </summary>
        /// <param name="value">Value to convert</param>
        /// <returns></returns>
        public static bool MySqlBool(string value)
        {
            if (value.Equals("Y"))
                return true;
            else
                return false;
        }

    }
}