本文主要是介绍PreparedStatementUpdateTest.java,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
package com.atguigu3.preparedstatement.crud;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Properties;
import org.junit.Test;
import com.atguigu1.connection.ConnectionTest;
import com.atguigu3.util.JDBCUtils;
/*
* 使用PreparedStatement来替换Statement,实现对数据表的增删改操作
*
* 增删改;查
*
*
*/
public class PreparedStatementUpdateTest {
@Test
public void testCommonUpdate(){
// String sql = "delete from customers where id = ?";
// update(sql,3);
String sql = "update `order` set order_name = ? where order_id = ?";
update(sql,"DD","2");
}
//通用的增删改操作
public void update(String sql,Object ...args){//sql中占位符的个数与可变形参的长度相同!
Connection conn = null;
PreparedStatement ps = null;
try {
//1.获取数据库的连接
conn = JDBCUtils.getConnection();
//2.预编译sql语句,返回PreparedStatement的实例
ps = conn.prepareStatement(sql);
//3.填充占位符
for(int i = 0;i < args.length;i++){
ps.setObject(i + 1, args[i]);//小心参数声明错误!!
}
//4.执行
ps.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
//5.资源的关闭
JDBCUtils.closeResource(conn, ps);
}
}
//修改customers表的一条记录
@Test
public void testUpdate(){
Connection conn = null;
PreparedStatement ps = null;
try {
//1.获取数据库的连接
conn = JDBCUtils.getConnection();
//2.预编译sql语句,返回PreparedStatement的实例
String sql = "update customers set name = ? where id = ?";
ps = conn.prepareStatement(sql);
//3.填充占位符
ps.setObject(1,"莫扎特");
ps.setObject(2, 18);
//4.执行
ps.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
//5.资源的关闭
JDBCUtils.closeResource(conn, ps);
}
}
// 向customers表中添加一条记录
@Test
public void testInsert() {
Connection conn = null;
PreparedStatement ps = null;
try {
// 1.读取配置文件中的4个基本信息
InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("jdbc.properties");
Properties pros = new Properties();
pros.load(is);
String user = pros.getProperty("user");
String password = pros.getProperty("password");
String url = pros.getProperty("url");
String driverClass = pros.getProperty("driverClass");
// 2.加载驱动
Class.forName(driverClass);
// 3.获取连接
conn = DriverManager.getConnection(url, user, password);
// System.out.println(conn);
//4.预编译sql语句,返回PreparedStatement的实例
String sql = "insert into customers(name,email,birth)values(?,?,?)";//?:占位符
ps = conn.prepareStatement(sql);
//5.填充占位符
ps.setString(1, "哪吒");
ps.setString(2, "nezha@gmail.com");
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date = sdf.parse("1000-01-01");
ps.setDate(3, new Date(date.getTime()));
//6.执行操作
ps.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
//7.资源的关闭
try {
if(ps != null)
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
if(conn != null)
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
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