Detailed explanation of the simple use of MySQL and sharing of JDBC sample code

MySql simple operation

<code>//启动mysql
net start mysql
 
//登陆
mysql -u root -p
 
 
//创建建数据库
create database mydb;
create database test;
 
//删除数据库
drop database test;
 
//使用数据库
use mydb;
 
//创建表
create table mytable（name varchar（20），sex char）;
 
//显示数据库中所有表
show tables;
 
//增加一列
alter table mytable add age int;
 
//插入
insert mytable value（"liu",&#39;f&#39;,22）;
insert mytable value（"wang",&#39;m&#39;,22）;
insert mytable(name,sex) value("li",&#39;f&#39;);
insert mytable value（"zhao",&#39;m&#39;,22）;
 
//删除表中项
delete from mytable where name=”liu“;
delete from mytable where name=”li“;
 
//更新
update mytable set age = 23 where name = "wang";
 
//查询
select * from mytable;
 
</code>

JDBC

JDBC driver is divided into 4 categories

JDBC-ODBC bridge part local API, part Java driver JDBC network pure Java driver Program local protocol Java driver

JDBC example

<code>import java.sql.*;
import com.mysql.jdbc.Driver;
public class JDBCMySql {
     
    public void operateMySql() throws SQLException, ClassNotFoundException{
         
        String driverName ="com.mysql.jdbc.Driver";
        String URL = "jdbc:mysql://127.0.0.1:3306/mydb";
        String sql = "SELECT * FROM mydb.mytable";
        String username = "root";
        String password = "";
        Connection conn = null;
        try{
         
        //加载驱动
        Driver.class.forName(driverName);
         
        //建立连接
        conn = DriverManager.getConnection(URL,username,password);
         
        //创建statement来执行sql语句
        Statement ps =  conn.createStatement();
         
        //结果集处理
        ResultSet rs = ps.executeQuery(sql);
        while(rs.next()) {        
        System.out.println(rs.getString("name")+","+rs.getString("sex")+","+rs.getInt("age"));    
            }
        }
        catch (ClassNotFoundException e) {
            e.printStackTrace();
        } 
        catch(SQLException e){
            e.printStackTrace();
        }
         
        //关闭连接
        finally{
            if(conn!=null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }   
    }   
}</code>

Create a test case to verify

<code>
import static org.junit.Assert.*;
 
import java.sql.SQLException;
 
import org.junit.Before;
import org.junit.Test;
 
public class JDBCTest {
 
    @Test
    public void test() throws ClassNotFoundException, SQLException {
        JDBCMySql jm = new JDBCMySql();
        jm.operateMySql();
    }
 
}</code>

Execution results

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