MySQL数据库(四)_使用MySql.Data.dll连接_读写mysql数据库

MySQL数据库(四)_使用MySql.Data.dll连接_读写mysql数据库<21/9/2017>

http://blog.csdn.net/liyuqian199695/article/details/53556639

1、下载 myql.data.all 下载地址如下

http://www.ddooo.com/softdown/43455.htm

2、 把myql.data.all放到工程debug文件夹下，引入到C#工程中，右键工程->添加->引用，选择myql.data.all，最后确认即可

3、相关代码如下：

using System;
using System.Configuration;
using MySql.Data.MySqlClient;
/// 

/// TestDatebase 的摘要说明
/// 
public class TestDatebase
{
    public TestDatebase()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    public static void Main ( String[] args )
    {
        MySqlConnection mysql = getMySqlCon();
        //查询sql
        String sqlSearch = "select * from student";
        //插入sql
        String sqlInsert = "insert into student values (12,'张三',25,'大专')";
        //修改sql
        String sqlUpdate = "update student set name='李四' where id= 3";
        //删除sql
        String sqlDel = "delete from student where id = 12";
        //打印SQL语句
        Console.WriteLine ( sqlDel );
        //四种语句对象
        //MySqlCommand mySqlCommand = getSqlCommand(sqlSearch, mysql);
        //MySqlCommand mySqlCommand = getSqlCommand(sqlInsert, mysql);
        //MySqlCommand mySqlCommand = getSqlCommand(sqlUpdate, mysql);
        MySqlCommand mySqlCommand = getSqlCommand ( sqlDel, mysql );
        mysql.Open();
        //getResultset(mySqlCommand);
        //getInsert(mySqlCommand);
        //getUpdate(mySqlCommand);
        getDel ( mySqlCommand );
        //记得关闭
        mysql.Close();
        String readLine = Console.ReadLine();
    }
    /// 

    /// 建立mysql数据库链接
    /// 
    /// 
    public static MySqlConnection getMySqlCon()
    {
        String mysqlStr = "Database=test;Data Source=127.0.0.1;User Id=root;Password=root;pooling=false;CharSet=utf8;port=3306";
        // String mySqlCon = ConfigurationManager.ConnectionStrings["MySqlCon"].ConnectionString;
        MySqlConnection mysql = new MySqlConnection ( mysqlStr );
        return mysql;
    }
    /// 

    /// 建立执行命令语句对象
    /// 
    /// 
    /// 
    /// 
    public static MySqlCommand getSqlCommand ( String sql,MySqlConnection mysql )
    {
        MySqlCommand mySqlCommand = new MySqlCommand ( sql, mysql );
        //  MySqlCommand mySqlCommand = new MySqlCommand(sql);
        // mySqlCommand.Connection = mysql;
        return mySqlCommand;
    }
    /// 

    /// 查询并获得结果集并遍历
    /// 
    /// 
    public static void getResultset ( MySqlCommand mySqlCommand )
    {
        MySqlDataReader reader = mySqlCommand.ExecuteReader();
        try
        {
            while ( reader.Read() )
            {
                if ( reader.HasRows )
                {
                    Console.WriteLine ( "编号:" + reader.GetInt32 ( 0 ) + "|姓名:" + reader.GetString ( 1 ) + "|年龄:" + reader.GetInt32 ( 2 ) + "|学历:" + reader.GetString ( 3 ) );
                }
            }
        }
        catch ( Exception )
        {
 
            Console.WriteLine ( "查询失败了！" );
        }
        finally
        {
            reader.Close();
        }
    }
    /// 

    /// 添加数据
    /// 
    /// 
    public static void getInsert ( MySqlCommand mySqlCommand )
    {
        try
        {
            mySqlCommand.ExecuteNonQuery();
        }
        catch ( Exception ex )
        {
            String message = ex.Message;
            Console.WriteLine ( "插入数据失败了！" + message );
        }
 
    }
    /// 

    /// 修改数据
    /// 
    /// 
    public static void getUpdate ( MySqlCommand mySqlCommand )
    {
        try
        {
            mySqlCommand.ExecuteNonQuery();
        }
        catch ( Exception ex )
        {
 
            String message = ex.Message;
            Console.WriteLine ( "修改数据失败了！" + message );
        }
    }
    /// 

    /// 删除数据
    /// 
    /// 
    public static void getDel ( MySqlCommand mySqlCommand )
    {
        try
        {
            mySqlCommand.ExecuteNonQuery();
        }
        catch ( Exception ex )
        {
            String message = ex.Message;
            Console.WriteLine ( "删除数据失败了！" + message );
        }
    }
}

实操补充:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data.MySqlClient;
namespace ToDB
{
    //数据库连接
    //1.拿到Connection开启
    //2.发送sql指令
    //3.让数据库来执行sql执行
    //4.拿到返回结果
    //5.关闭数据库
    //**Main数据插入**//
    //MySqlCommand myCmd = new MySqlCommand("insert into student values(38,'郭明杰','woman',1）", myConnnect);
    //Console.WriteLine(myCmd.CommandText);
    //if (myCmd.ExecuteNonQuery() > 0)
    //{
    //    Console.WriteLine("数据插入成功！");
    //}
    //**Main数据插入**//
    //**Main数据删除**//
    //myCmd.CommandText = "delete from t_dept";
    //Console.WriteLine(myCmd.CommandText);
    //if (myCmd.ExecuteNonQuery() > 0)
    //{
    //    Console.WriteLine("user表类型数据全部删除成功！");
    //}
    //**Main数据删除**//
    //myCmd.Dispose();
    class Program
    {
        static void Main(string[] args)
        {
            string constructorString = "server=localhost;User Id=root;password=;Database=vr";
            MySqlConnection myConnnect = new MySqlConnection(constructorString);
            myConnnect.Open();
            MySqlCommand myCmd1 = new MySqlCommand("select * from student", myConnnect);
            GetResultset(myCmd1);
            //MySqlCommand myCmd2 = new MySqlCommand("insert into student values(17,'liubei','man',3)",myConnnect);
            MySqlCommand myCmd3 = new MySqlCommand("update student set gender='nn' where class_id=1", myConnnect);
            int a = myCmd3.ExecuteNonQuery();//返回一个整数,表示执行受影响的行数
            Console.WriteLine(a);
            myConnnect.Close();
            Console.WriteLine(myConnnect);
        }
        public static void GetResultset(MySqlCommand mySqlCommand)
        {
            MySqlDataReader reader = mySqlCommand.ExecuteReader();
            try
            {
                while (reader.Read())
                {
                    if (reader.HasRows)
                    {
                        Console.WriteLine("sid:" + reader.GetInt32(0) + " sname:" + reader.GetString(1) + " gender:" + reader.GetString(2) + " class_id:" + reader.GetInt32(3));
                    }
                }
            }
            catch (Exception)
            {

                Console.WriteLine("查询失败了！");
            }
            finally
            {
                reader.Close();
            }
        }
    }
}

使用update...set...根据条件更改目标项:

关于MySqlDataReader的用法解析:

Execute补充:

//MySqlDataReader reader = comd.ExecuteReader();
            //while (reader.Read())
            //{
            //    Console.WriteLine(reader.GetValue(0)+" \t"+reader.GetValue(1)+"      \t"+ reader.GetValue(2));
            //}
            //******Execute类型三选一只能同时执行一个,多个同时会报错******//
            object o = comd.ExecuteScalar();//返回第一个数据
            Console.WriteLine(o);