JdbcTemplate概述

它是spring框架中提供的一个对象，是对原始繁琐的JdbcAPI对象的简单封装。spring框架为我们提供了很多的操作模板类。例如:操作关系型数据的JdbcTemplate和MbernateTemplate，操作nosql数据库的RedisTemplate，操作消息队列的JmsTemplate等等。

JdbcTemplate开发步骤

① 导入spring-jdbc和spring-tx坐标

② 创建数据库表和实体

③ 创建JdbcTemplate对象

④ 执行数据库操作

@Test
    // 测试JdbcTemplate的开发步骤
    public void test2() throws PropertyVetoException {
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        JdbcTemplate jdbcTemplate = app.getBean(JdbcTemplate.class);
        int row = jdbcTemplate.update("insert into account values(?, ?)", "lisi11", 1000);
        System.out.println(row);
    }

//-----------------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">


<!--    加载jdbc.properties-->
    <context:property-placeholder location="classpath:jdbc.properties"/>

<!--    数据源对象-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

<!--    jdbc模板对象-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

//----------------------------------------------

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=1234

 JdbcTemplate基本使用-常用操作-更新删除操作

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Test
    public void testUpdate(){
        jdbcTemplate.update("update account set money = ? where name = ?",10001, "wangwu");
    }

    @Test
    public void testDelete(){
        jdbcTemplate.update("delete from account where money = ?", 10001);
    }
}

 JdbcTemplate基本使用-常用操作-查询操作

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Test
    public void testUpdate(){
        jdbcTemplate.update("update account set money = ? where name = ?",10001, "wangwu");
    }

    @Test
    public void testDelete(){
        jdbcTemplate.update("delete from account where money = ?", 10001);
    }

    //查询多个
    @Test
    public void estQuery(){
        List<Account> accountList = jdbcTemplate.query("select * from account", new BeanPropertyRowMapper<Account>(Account.class));
        System.out.println(accountList);
    }

    //查询一个
    @Test
    public void testQueryOne(){
        List<Account> accountList = jdbcTemplate.query("select * from account where name=?", new BeanPropertyRowMapper<Account>(Account.class), "lisi");
        System.out.println(accountList);

    }

    //聚合查询
    @Test
    public void testQueryCount(){
        Long count = jdbcTemplate.queryForObject("select count(*) from account", Long.class);
        System.out.println(count);
    }
}