package cn.chuang.JdbcDome;

 import java.sql.*;

 public class JdbcDome3 {

     public static void main(String[] args) throws Exception {

         PreparedStatement ppst = null;

         Connection conn = null;

         fun3(ppst,conn);

     }

     public static void fun1(PreparedStatement ppst,Connection conn) throws Exception {

         //查询表的内容

         //1 注册驱动 获得Connection

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

         //2 获得链接

         conn = DriverManager.getConnection("jdbc:mysql:///semployee", "root", "root");

         //3 sql语句

         String sql = "select * from lll";

         //4 获得执行sql语句的对象

         ppst = conn.prepareStatement(sql);

         ResultSet rs = ppst.executeQuery(sql);

         //5 让游标向下移动一行

         rs.next();

         int i = rs.getInt(1);

         String name = rs.getString("ename");

         //6 获取数据

         System.out.println(i+"  "+name);

     }
    

     public static void fun2(PreparedStatement ppst,Connection conn) throws Exception {

         //在表中添加数据，表结构有多少就要写多少。不能漏写，会报错。

         try {

             //1 注册驱动 获得Connection

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

             //2 获得链接

             conn = DriverManager.getConnection("Jdbc:mysql:///semployee", "root", "root");

             //3 sql语句

             String sql = "insert into lll values (null,'兀立扗'),(null,'吴诗意')";

             //4 获得执行sql语句的对象

             ppst = conn.prepareStatement(sql);

             int i = ppst.executeUpdate(sql);

             //5 处理结果

             System.out.println(i);

             //6 另创建if语句，做提示用。

             if (i>0){

                 System.out.println("添加成功");

             }else{

                 System.out.println("添加失败");

             }

         } catch (Exception e) {

             e.printStackTrace();

         }finally {

             if(ppst!=null){

                 try {

                     ppst.close();

                 } catch (SQLException e) {

                     e.printStackTrace();

                 }

             }

             if (conn!=null){

                 try {

                     conn.close();

                 } catch (SQLException e) {

                     e.printStackTrace();

                 }

             }

         }

     }
    

 public static void fun3(PreparedStatement ppst,Connection conn) throws Exception {

        //删除表内数据。

        //1 注册驱动 获得Connection

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

        conn = DriverManager.getConnection("jdbc:mysql:///semployee", "root", "root");

        //2 sql语句

        String sql = "delete from lll where uid = 2";

        //3 获得执行sql语句的对象Statement

        ppst = conn.prepareStatement(sql);

        int i = ppst.executeUpdate(sql);

        //4 处理结果

        System.out.println(i);

        if (i>0){

            System.out.println("删除成功");

            ppst.close();

            conn.close();

        }else{

            System.out.println("删除失败");

        }

    }

 public static void fun4(PreparedStatement ppst,Connection conn) throws Exception {
　　　　　　//修改表内数据

         //1 注册驱动。

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

         //2 链接数据库。

         conn = DriverManager.getConnection("jdbc:mysql:///semployee", "root", "root");

         //3 SQL语句。

         String sql = "update lll set  uname = '吴惆' where uid = 1  ";

         //4 获得执行SQL的语句。

         ppst = conn.prepareStatement(sql);

         //5 处理结果。

         int ou = ppst.executeUpdate(sql);

         System.out.println(ou);

     }

 }