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c#操作mysql數據庫

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1、下載mysql.Data.dll,在解決方案->引用中引入,並在文件頭部引入

using MySql.Data.MySqlClient;

2、創建MySqlConnection對象(鏈接庫)

string connstr = "data source=localhost;database=cs_test;user id=root;password=123456;pooling=false;charset=utf8";//pooling代表是否使用連接池
MySqlConnection conn = new MySqlConnection(connstr);

3、創建對應操作的MySqlCommand對象(測試數據庫表名characters,屬性列:id,names,passwords)

string sql = "select * from characters";
MySqlCommand cmd = new MySqlCommand(sql,conn);

4、針對不同操作,MySqlCommand對象有三個常用方法

(1)查找多行 : ExecuteReader()方法

返回一個MysqlDataReader對象,包含多個行,可以用其Read方法逐行讀取。

對於每行元素,可以用getXXX()方法讀取屬性值,XXX為該屬性類型,參數為屬性名或者該屬性為這張表的第幾列。

可以用IsDBNull()方法判斷是否為空,參數只能是該屬性為這張表的第幾列(即只能是數字)

    conn.Open();
    MySqlDataReader reader = cmd.ExecuteReader();
    Console.WriteLine("id\t姓名\t密碼");
    while (reader.Read())
    {
        Console.Write(reader.GetInt32("id")+"\t");
        if (reader.IsDBNull(1))
        {
            Console.Write("空\t");
        }
        else
        {
            Console.Write(reader.GetString(
"names")+"\t"); } if (reader.IsDBNull(2)) { Console.Write("空\n"); } else { Console.Write(reader.GetString("passwords")+"\n"); } } conn.Close();

(2)查找單個: ExecuteScalar()

返回值為查找到的元祖第一個屬性,以object類型返回

string sql2 = "select names from characters where id=2";
MySqlCommand cmd2 = new MySqlCommand(sql2,conn);
conn.Open();
string names = cmd2.ExecuteScalar().ToString();
Console.WriteLine(names);
conn.Close();

(3)增、刪、改: ExecuteNonQuery()

返回值為int,不成功是0,成功是1

string sql3 = "insert into characters (names,passwords) values (‘XXX‘,‘1234456‘)";
MySqlCommand cmd3 = new MySqlCommand(sql3,conn);
conn.Open();
int s = cmd3.ExecuteNonQuery();
if (s == 0) 
Console.WriteLine("false");
else 
Console.WriteLine("success");
conn.Close();

5、完整代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;

namespace mysql_test
{
    class mysqlcz{
        public mysqlcz()
        {
            string connstr = "data source=localhost;database=csceshi;user id=root;password=123456;pooling=false;charset=utf8";
            using (MySqlConnection conn = new MySqlConnection(connstr))
            {
                string sql = "select * from characters";
                MySqlCommand cmd = new MySqlCommand(sql,conn);
                conn.Open();
                MySqlDataReader reader = cmd.ExecuteReader();
                Console.WriteLine("id\t姓名\t密碼");
                while (reader.Read())
                {
                    Console.Write(reader.GetInt32("id")+"\t");
                    if (reader.IsDBNull(1))
                    {
                        Console.Write("空\t");
                    }
                    else
                    {
                        Console.Write(reader.GetString("names")+"\t");
                    }

                    if (reader.IsDBNull(2))
                    {
                        Console.Write("空\n");
                    }
                    else
                    {
                        Console.Write(reader.GetString("passwords")+"\n");
                    }
                }
                conn.Close();
string sql2 = "select names from characters where id=2"; MySqlCommand cmd2 = new MySqlCommand(sql2,conn); conn.Open(); string names = cmd2.ExecuteScalar().ToString(); Console.WriteLine(names); conn.Close(); string sql3 = "insert into characters (names,passwords) values (‘XXX‘,‘1234456‘)"; MySqlCommand cmd3 = new MySqlCommand(sql3,conn); conn.Open(); int s = cmd3.ExecuteNonQuery(); if (s == 0) Console.WriteLine("false"); else Console.WriteLine("success"); conn.Close(); } Console.ReadLine(); } } class Program { static void Main(string[] args) { mysqlcz mt = new mysqlcz(); } } }

c#操作mysql數據庫