asp.net使用mysql数据库

Asp.net连接mysql 不推荐使用ODBC,推荐是用mysql官网提供的组件MySQL.Data.Dll，放在bin下面，添加引用即可

下面是封装的几个常用操作

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using MySql.Data.MySqlClient;
 using System.Data;
 using System.Text;

 namespace WebApplication2
 {
     public class DBHelper
     {
         public static string connectionString = "Host=127.0.0.1;UserName=root;Password=root;"
             +"Database=mmloo;Port=3306;CharSet=utf8;Allow Zero Datetime=true";

         public DBHelper(){}

         public static string DataTableToJson(DataTable dt)
         {
             StringBuilder jsonBuilder = new StringBuilder();
             jsonBuilder.Append("{\"");
             jsonBuilder.Append(dt.TableName);
             jsonBuilder.Append("\":[");
             jsonBuilder.Append("[");
             for (int i = ; i < dt.Rows.Count; i++)
             {
                 jsonBuilder.Append("{");
                 for (int j = ; j < dt.Columns.Count; j++)
                 {
                     jsonBuilder.Append("\"");
                     jsonBuilder.Append(dt.Columns[j].ColumnName);
                     jsonBuilder.Append("\":\"");
                     jsonBuilder.Append(dt.Rows[i][j].ToString());
                     jsonBuilder.Append("\",");
                 }
                 jsonBuilder.Remove(jsonBuilder.Length - , );
                 jsonBuilder.Append("},");
             }
             jsonBuilder.Remove(jsonBuilder.Length - , );
             jsonBuilder.Append("]");
             jsonBuilder.Append("}");
             return jsonBuilder.ToString();
         }
         /// <summary>
         /// 执行sql语句，返回影响的记录数
         /// </summary>
         /// <param name="SQLString"></param>
         /// <returns></returns>
         public static int ExecuteNonQuery(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;
                     }
                 }
             }
         }

         /// <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 ExecuteNonQuery(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>
         /// 执行查询语句，返回DataTable
         /// </summary>
         /// <param name="SQLString">查询语句</param>
         /// <returns>DataTable</returns>
         public static DataTable ExecuteDataTable(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.Tables[];
             }
         }

         /// <summary>
         /// 执行查询语句，返回DataSet
         /// </summary>
         /// <param name="SQLString">查询语句</param>
         /// <returns>DataTable</returns>
         public static DataTable ExecuteDataTable(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.Tables[];
                 }
             }
         }

         /// <summary>
         /// 创建cmd
         /// </summary>
         /// <param name="cmd"></param>
         /// <param name="conn"></param>
         /// <param name="trans"></param>
         /// <param name="cmdText"></param>
         /// <param name="cmdParms"></param>
         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);
                 }
             }
         }

     }
 }