一、常用属性

using MySql.Data.MySqlClient;using System;using System.Data.Common;namespace ConsoleApp{ class Program { static void Main(string[] args) { string str = string.Format("Server={0};Port={1};Database={2};Uid={3};Pwd={4};", "localhost", 3306, "wisdompurchase", "root", "1234"); DbConnection conn = new MySqlConnection(str); //创建连接 //连接的数据库名称 DbCommand cmd = conn.CreateCommand(); cmd.CommandText = "Update Person Set Name = ‘Ado.net修改‘ WHERE Id = @Id"; //设置操作语句 //看看默认的发生错误等待时间(秒) Console.WriteLine(cmd.CommandTimeout); //30 //指明CommandText是SQL语句，存储过程还是表操作。枚举类型，转到定义可看 Console.WriteLine(cmd.CommandType); //输出 Text 表示这是一条SQL语句 //SqlCommand的SqlConnection实例对象 Console.WriteLine(cmd.Connection.ConnectionString); //"server=.;database=JunTest;uid=sa;pwd=123"; //设置参数值 cmd.Parameters.Add(new MySqlParameter("@Id", 1)); Console.WriteLine(cmd.Parameters["@Id"].Value); //输出1 conn.Open(); conn.Close(); Console.ReadKey(); } }}

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二、常用方法

　　1、ExecuteNonQuery()　　增删改操作

　　增、删、改都是这个：

using MySql.Data.MySqlClient;using System;using System.Data.Common;namespace ConsoleApp{ class Program { static void Main(string[] args) { string str = string.Format("Server={0};Port={1};Database={2};Uid={3};Pwd={4};", "localhost", 3306, "wisdompurchase", "root", "1234"); DbConnection conn = new MySqlConnection(str); //创建连接 //连接的数据库名称 DbCommand cmd = conn.CreateCommand(); //创建命令 cmd.CommandText = "Update t_s_base_user Set realname = ‘李伟斌‘ WHERE Id = @Id"; //设置操作语句 cmd.Parameters.Add(new MySqlParameter("@Id",MySqlDbType.VarChar)); //设置参数值 cmd.Parameters["@Id"].Value = 1; conn.Open(); //打开连接 int i = cmd.ExecuteNonQuery(); //执行命令，ExecuteNonQuery由名称看出，只能用于非查询语句 conn.Close(); //关闭连接 Console.WriteLine(i); //输出影响行数 Console.ReadKey(); } }}

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　　2、ExecuteScalar() 　　返回第一行第一列
　　3、ExecuteReader()　　创建一个SqlDataReader用于读取数据

using MySql.Data.MySqlClient;using System;using System.Data.Common;namespace ConsoleApp{ class Program { static void Main(string[] args) { string str = string.Format("Server={0};Port={1};Database={2};Uid={3};Pwd={4};", "localhost", 3306, "wisdompurchase", "root", "1234"); DbConnection conn = new MySqlConnection(str); //创建连接 //连接的数据库名称 DbCommand cmd = conn.CreateCommand(); //创建命令 cmd.CommandText = "SELECT * FROM `t_s_base_user` LIMIT 5"; //设置操作语句 conn.Open(); //打开连接 //SqlDataReader读取数据 using (DbDataReader reader = cmd.ExecuteReader()) { while (reader.Read()) { Console.WriteLine(reader[0] + ":" + reader[1]); //输出当前行的第一列，第二列数据 } } cmd.CommandText = "SELECT Count(*) FROM `t_s_base_user`"; object obj = cmd.ExecuteScalar(); //仅查询第一行第一列 Console.WriteLine(Convert.ToInt32(obj)); conn.Close(); //关闭连接 Console.ReadKey(); } }}

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　　4、ExecuteXmlReader()　　返回System.XmlReader实例，用于读取SQLServer中的XML字段的值

　　首先建一张表如下：

/*SQLyog Ultimate v11.33 (64 bit)MySQL - 5.7.17-log **********************************************************************//*!40101 SET NAMES utf8 */;insert into `article` (`ArticleId`, `ArticleInfo`) values(‘1‘,‘<Article><author age=\"30\">张三</author><length>12000</length><price>42</price></Article>‘);

ArticleSql

　　其中ArticleInfo字段的数据类型为xml，值为：

　　<Article><author age="30">张三</author><length>12000</length><price>42</price></Article>

　　下面，我们使用ExecuteXmlReader()读取出author的值：　　

using System;using System.Data.Common;using System.IO;using System.Xml;namespace ConsoleApp{ public static class ExtensionDbCommand { public static XmlReader ExecuteXmlReader(this DbCommand cmd) { object obj = cmd.ExecuteScalar(); //仅查询第一行第一列 if (obj == null) return null; StringReader strRdr = new StringReader(Convert.ToString(obj)); return XmlReader.Create(strRdr); } }}

ExtensionDbCommand

using MySql.Data.MySqlClient;using System;using System.Data.Common;using System.Xml;namespace ConsoleApp{ class Program { static void Main(string[] args) { string str = string.Format("Server={0};Port={1};Database={2};Uid={3};Pwd={4};", "localhost", 3306, "wisdompurchase", "root", "1234"); DbConnection conn = new MySqlConnection(str); //创建连接 //连接的数据库名称 DbCommand cmd = conn.CreateCommand(); //创建命令 conn.Open(); //打开连接 cmd.CommandText = "SELECT ArticleInfo FROM Article LIMIT 1"; //查询XML字段 using (XmlReader reader = cmd.ExecuteXmlReader()) //由Command实例返回XmlReader的实例 { while (reader!=null && reader.Read()) { if (reader.Name == "author") { Console.WriteLine(reader.ReadInnerXml()); //输出张三 } } } conn.Close(); Console.ReadKey(); } }}

Program

　还有就是以上这些方法的异步版本，本处仅以以下两个方法示例:

　　5、BeginExecuteNonQuery()　异步版ExecuteNonQuery()

　　6、EndExecuteNonQuery()　　异步版ExecuteNonQuery()

using MySql.Data.MySqlClient;using System;using System.Data.Common;namespace ConsoleApp{ class Program { static void Main(string[] args) { string str = string.Format("Server={0};Port={1};Database={2};Uid={3};Pwd={4};", "localhost", 3306, "wisdompurchase", "root", "1234"); DbConnection conn = new MySqlConnection(str); //创建连接 //连接的数据库名称 MySqlCommand cmd = (MySqlCommand)conn.CreateCommand(); //创建命令 cmd.CommandText = "INSERT INTO `article` VALUES(2,‘郭嘉‘)"; //设置操作语句 conn.Open(); //打开连接 cmd.BeginExecuteNonQuery(BeginCallback, cmd); //异步执行语句 Console.WriteLine("不管你执没执行完，我继续做我的事!"); Console.ReadKey(); } static void BeginCallback(IAsyncResult result) { Console.WriteLine("正在执行SQL命令!"); MySqlCommand cmd = result.AsyncState as MySqlCommand; //获得异步传入的参数 Console.WriteLine("成功执行命令：" + cmd.CommandText); Console.WriteLine("本次执行影响行数为：" + cmd.EndExecuteNonQuery(result)); Console.WriteLine("关闭连接!"); cmd.Connection.Close(); //正式关闭连接 } }}

Program