MySQL的簡單使用和JDBC示例

MySql簡單操作

//啟動mysql
net start mysql

//登陸
mysql -u root -p


//創建建資料庫
create database mydb;
create database test;

//刪除資料庫
drop database test;

//使用資料庫
use mydb;

//創建表
create table mytable（name varchar（20），sex char）;

//顯示資料庫中所有表
show tables;

//增加一列
alter table mytable add age int;

//插入
insert mytable value（"liu",'f',22）;
insert mytable value（"wang",'m',22）;
insert mytable(name,sex) value("li",'f');
insert mytable value（"zhao",'m',22）;

//刪除表中項
delete from mytable where name=”liu“;
delete from mytable where name=”li“;

//更新
update mytable set age = 23 where name = "wang";

//查詢
select * from mytable;

JDBC

• JDBC驅動程式分為4類
  • JDBC-ODBC橋
  • 部分本地API，部分Java驅動程式
  • JDBC網路純Java驅動程式
  • 本地協議Java驅動程式

JDBC的示例

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{
        
        //載入驅動
        Driver.class.forName(driverName);
        
        //建立連接
        conn = DriverManager.getConnection(URL,username,password);
        
        //創建statement來執行sql語句
        Statement ps =  conn.createStatement();
        
        //結果集處理
        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();
        }
        
        //關閉連接
        finally{
            if(conn!=null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }   
    }   
}

建立一個test case來驗證一下

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();
    }

}

執行結果