jdbc模板的基本使用

1.JdbcTemplate的开发步骤

        <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

2.JdbcTemplate快速入门

        <1>导入坐标

        

<dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>5.0.5.RELEASE</version></dependency>

        <2>创建实体类和表

package com.lin.domain;public class Account {private String name;private double money;public Account() {}public Account(String name, double money) {this.name = name;this.money = money;}public String getName() {return name;}public double getMoney() {return money;}public void setName(String name) {this.name = name;}public void setMoney(double money) {this.money = money;}@Overridepublic String toString() {return "Account{" +"name='" + name + '\'' +", money=" + money +'}';}
}

 <3>创建jdbcTemplate对象

<4>执行数据库操作

@Test//测试JdbcTemplate开发步骤public void test1() throws PropertyVetoException {//        创建数据源对象ComboPooledDataSource dataSource=new ComboPooledDataSource();dataSource.setDriverClass("com.mysql.jdbc.Driver");dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");dataSource.setUser("root");dataSource.setPassword("123456");JdbcTemplate jdbcTemplate=new JdbcTemplate();//设置数据源对象，知道数据库在哪jdbcTemplate.setDataSource(dataSource);//执行操作int row = jdbcTemplate.update("insert into account value (?,?)", "wu", 12);System.out.println(row);}

3.spring 产生jdbcTemplate对象

可以将数据源DateSource的创建权交给Spring，在Spring容器内部将数据源注入到模板中

spring容器加载外部properties文件时必须添加context命名空间

 <!--加载properties文件 添加context命名空间--><context:property-placeholder location="classpath:jdbc.properties"/><!--配置数据源对象--><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>

4.crud操作

package com.lin.test;import com.lin.domain.Account;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import java.util.List;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class CrudTest {@Autowired
//    测试谁注入谁private JdbcTemplate jdbcTemplate;@Testpublic void testUpdate(){int row = jdbcTemplate.update("update account set money=? where name=?", 100000, "ws");System.out.println(row);}@Testpublic void testDelete(){int row = jdbcTemplate.update("delete from account where name=?",  "ws");System.out.println(row);}//查询所有@Testpublic void testQueryAll(){List<Account> list = jdbcTemplate.query("select *from account", new BeanPropertyRowMapper<Account>(Account.class));System.out.println(list);}@Test//单个查询时返回一个对象public void testQueryOne(){Account account = jdbcTemplate.queryForObject("select * from account where name=?", new BeanPropertyRowMapper<Account>(Account.class), "wu");System.out.println(account);}//聚合查询@Testpublic void testQueryCount(){Long count = jdbcTemplate.queryForObject("select count(*) from account", Long.class);System.out.println(count);}
}

5.小节

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

        JdbcTemplate jdbcTemplate = new JdbcTemplate();

        jdbcTemplate.setDataSource(dataSource);

④ 执行数据库操作

        更新操作：

        jdbcTemplate.update (sql,params)

        查询操作：

        jdbcTemplate.query (sql,Mapper,params)

        jdbcTemplate.queryForObject(sql,Mapper,params)