java连接mysql与简单操作mysql的增删改查简单例子

package DB;

import java.sql.*;

public class DB{

//加载驱动

String Driver="com.mysql.jdbc.Driver";

//路径

String url="jdbc:mysql://localhost:3306/student";

String userName="root";

String userPass="admin";

Connection conn=null;

Statement st=null;

ResultSet rs=null;

//连接数据库

public DB(){

try {

Class.forName("com.mysql.jdbc.Driver");

//连接数据库

this.conn=DriverManager.getConnection(url, userName, userPass);

//创建连接状态

this.st=conn.createStatement();

// st.executeQuery(sql);

System.out.println("连接成功");

} catch (Exception e) {

// TODO: handle exception

}

}

//操作查询方法

public ResultSet executeQuery1(String strsql){

try {

//System.out.println("1");

this.rs=st.executeQuery(strsql);

return this.rs;

} catch (SQLException e) {

// TODO: handle exception

System.out.println("空指针");

return null;

}catch(NullPointerException e){

System.out.println("kong");

return null;

}

}

//插入数据

public boolean insert(String strsql){

try {

Statement st=this.conn.createStatement();

int i=st.executeUpdate(strsql);

if(i!=0){

System.out.println("插入数据了");

return true;

}else{

return false;

}

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

System.out.println("SQL异常");

return false;

}catch(NullPointerException e){

System.out.println("空指针");

return false;

}

}

//删除数据

public boolean delete(String strsql){

try {

Statement st=this.conn.createStatement();

st.executeUpdate(strsql);

return true;

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}catch(NullPointerException e){

return false;

}

return false;

}

//更行数据

public boolean update(String strsql){

try {

Statement st=this.conn.createStatement();

st.executeUpdate(strsql);

System.out.println("更新数据成功");

return true;

} catch (Exception e) {

// TODO: handle exception

return false;

}

}

}

下面是测试类

import java.sql.ResultSet;

import java.sql.SQLException;

import DB.DB;

public class Test {

public static void main(String[] args) {

DB dao=new DB();

ResultSet rs=null;

//查询数据

try {

String strsql="select * from student";

rs=dao.executeQuery1(strsql);

while(rs.next()){

String str1=rs.getString(1);

// String str2=rs.getString(2);

System.out.println(str1+":"+"");

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

//插入数据

try {

String strsql="insert into student(name,age,stuid)value('koko','20','113')";

dao.insert(strsql);

} catch (Exception e) {

// TODO: handle exception

}

//删除数据

try {

String strsql="delete from student where name='xie'";

dao.delete(strsql);

} catch (Exception e) {

// TODO: handle exception

}

//更新数据

try {

String strsql="update student set NAME='xie' where NAME='xue'";

dao.update(strsql);

System.out.println("更新数据成功");

} catch (Exception e) {

// TODO: handle exception

}

}

}