Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之03.JDBC Statement(2)

2021-12-24 00:32:08

• Update

TestStatement.java

package com.michael.jdbc;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

public class TestStatement {
        public static void getStatement(){
                Connection conn = new ConnectionUtil().openConnection();
                try {
                        Statement stmt = conn.createStatement();
                        System.out.println(stmt);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }
        public static void createTable(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "create table CustomerTbl(id int primary key auto_increment,name varchar(20),email varchar(20))";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        stmt.execute(sql);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
        //DML数据操作语句--CRUD:create、retrive、update、delete
        public static void testUpdate(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "update CustomerTbl set name='Redking' where id=1";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        stmt.executeUpdate(sql);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
}

Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发之03.JDBC Statement(2)

Main.java

package com.michael.main;

import com.michael.jdbc.ConnectionUtil;
import com.michael.jdbc.TestStatement;

public class Main {

        /**
         * @param args
         */
        public static void main(String[] args) {
                ConnectionUtil cu = new ConnectionUtil();
                //第一种方法
                System.out.println("第一种方法:"+cu.getConnection());
                //第二种方法
                System.out.println("第二种方法:"+cu.getConnection("com.mysql.jdbc.Driver","jdbc:mysql://localhost:3306/jdbc_db","root","mysqladmin"));
                //第三种方法
                System.out.println("第三种方法:"+cu.openConnection());
                TestStatement.getStatement();
                //TestStatement.createTable();
                TestStatement.testUpdate();
        }

}

测试结果：

• delete

TestStatement.java

package com.michael.jdbc;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

public class TestStatement {
        public static void getStatement(){
                Connection conn = new ConnectionUtil().openConnection();
                try {
                        Statement stmt = conn.createStatement();
                        System.out.println(stmt);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }
        public static void createTable(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "create table CustomerTbl(id int primary key auto_increment,name varchar(20),email varchar(20))";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        stmt.execute(sql);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
        //DML数据操作语句--CRUD:create、retrive、update、delete
        public static void testDelete(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "delete from CustomerTbl";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        stmt.executeUpdate(sql);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
}

Main.java

测试结果：

增删改三个操作都是使用的executeUpdate()方法

• 使用Statement 执行DML
–查询
TestStatement.java

package com.michael.jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class TestStatement {
        public static void getStatement(){
                Connection conn = new ConnectionUtil().openConnection();
                try {
                        Statement stmt = conn.createStatement();
                        System.out.println(stmt);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }
        public static void createTable(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "create table CustomerTbl(id int primary key auto_increment,name varchar(20),email varchar(20))";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        stmt.execute(sql);
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
        //DML数据操作语句--CRUD:create、retrive、update、delete
        public static void testQuery(){
                //DDL数据定义语句
                Connection conn = new ConnectionUtil().openConnection();
                String sql = "select * from CustomerTbl";
                try {
                        Statement stmt = conn.createStatement();
                        //执行SQL语句
                        ResultSet rs = stmt.executeQuery(sql);
                        while(rs.next()){
                                //可以通过列索引
                                int id = rs.getInt(1);
                                //可以通过列名称
                                String name = rs.getString("name");
                                String email = rs.getString(3);
                                System.out.println(id+":"+name+":"+email);
                        }
                } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }finally{
                        if(conn!=null)
                                try {
                                        conn.close();
                                } catch (SQLException e) {
                                        conn = null;
                                        e.printStackTrace();
                                }
                }
        }
}

Main.java

测试结果：

先在数据库中添加几个数据，我们只测试下查询效果哈~

#################Michael分割线#########################

Java EE WEB工程师培训-JDBC+Servlet+JSP整合开发技术讨论技术圈：[url]http://g.51cto.com/itedu[/url]

#################Michael分割线#########################

本文转自redking51CTO博客，原文链接：http://blog.51cto.com/redking/151714，如需转载请自行联系原作者

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