标签：mysql tor odi mysq 实体 集合 属性 dao pac
在src下面新建一个属性配置文件
1 jdbc.user=root
2 jdbc.password=123456
3 jdbc.driverClass=com.mysql.jdbc.Driver
4 jdbc.jdbcUrl=jdbc\:mysql\:///test
配置Spring配置文件applicationContext.xml
1 <context:property-placeholder location="classpath:db.properties"/>
2 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
3 <property name="user" value="${jdbc.user}"></property>
4 <property name="password" value="${jdbc.password}"></property>
5 <property name="driverClass" value="${jdbc.driverClass}"></property>
6 <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
7 </bean>
8
9 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
10 <property name="dataSource" ref="dataSource"></property>
11 </bean>
a、通过update插入数据
1 //启动IoC容器
2 ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext.xml");
3 //获取IoC容器中JdbcTemplate实例
4 JdbcTemplate jdbcTemplate=(JdbcTemplate) ctx.getBean("jdbcTemplate");
5 String sql="insert into user (name,deptid) values (?,?)";
6 int count= jdbcTemplate.update(sql, new Object[]{"caoyc",3});
7 System.out.println(count);
2、batchUpdate()批量插入、更新和删除方法
a、批量插入
1 String sql="insert into user (name,deptid) values (?,?)";
2
3 List<Object[]> batchArgs=new ArrayList<Object[]>();
4 batchArgs.add(new Object[]{"caoyc",6});
5 batchArgs.add(new Object[]{"zhh",8});
6 batchArgs.add(new Object[]{"cjx",8});
7
8 jdbcTemplate.batchUpdate(sql, batchArgs);
batchUpdate方法第二参数是一个元素为Object[]数组类型的List集合
3、从数据中读取数据到实体对象
先定一个User实体类
1 package com.proc;
2
3 public class User {
4 private Integer id;
5 private String name;
6 private Integer deptid;
7 public Integer getId() {
8 return id;
9 }
10 public void setId(Integer id) {
11 this.id = id;
12 }
13 public String getName() {
14 return name;
15 }
16 public void setName(String name) {
17 this.name = name;
18 }
19 public Integer getDeptid() {
20 return deptid;
21 }
22 public void setDeptid(Integer deptid) {
23 this.deptid = deptid;
24 }
25
26 public String toString() {
27 return "User [id=" + id + ", name=" + name + ", deptid=" + deptid + "]";
28 }
29 }
a、读取单个对象
1 String sql="select id,name,deptid from user where id=?"; 2 3 RowMapper<User> rowMapper=new BeanPropertyRowMapper<User>(User.class); 4 User user= jdbcTemplate.queryForObject(sql, rowMapper,52); 5 System.out.println(user);
输出结果：
User [id=52, name=caoyc, deptid=6]
【注意】：1、使用BeanProperytRowMapper要求sql数据查询出来的列和实体属性需要一一对应。如果数据中列明和属性名不一致，在sql语句中需要用as重新取一个别名
2、使用JdbcTemplate对象不能获取关联对象
b、读取多个对象
1 String sql="select id,name,deptid from user";
2
3 RowMapper<User> rowMapper=new BeanPropertyRowMapper<User>(User.class);
4 List<User> users= jdbcTemplate.query(sql, rowMapper);
5 for (User user : users) {
6 System.out.println(user);
7 }
输出结果
...
User [id=49, name=姓名49, deptid=5]
User [id=50, name=姓名50, deptid=8]
User [id=52, name=caoyc, deptid=6]
User [id=53, name=zhh, deptid=8]
User [id=54, name=cjx, deptid=8]
---
c、获取某个记录某列或者count、avg、sum等函数返回唯一值
1 String sql="select count(*) from user"; 2 3 int count= jdbcTemplate.queryForObject(sql, Integer.class); 4 System.out.println(count);
在实际开发中可以怎样用
UserDao.java
1 package com.proc;
2
3 import org.springframework.beans.factory.annotation.Autowired;
4 import org.springframework.jdbc.core.BeanPropertyRowMapper;
5 import org.springframework.jdbc.core.JdbcTemplate;
6 import org.springframework.jdbc.core.RowMapper;
7 import org.springframework.stereotype.Repository;
8
9 @Repository
10 public class UserDao {
11
12 @Autowired
13 private JdbcTemplate jdbcTemplate;
14
15 public User get(int id){
16 String sql="select id,name,deptid from user where id=?";
17 RowMapper<User> rowMapper=new BeanPropertyRowMapper<User>(User.class);
18 return jdbcTemplate.queryForObject(sql, rowMapper,id);
19 }
20 }
xml配置：
1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xmlns:aop="http://www.springframework.org/schema/aop"
5 xmlns:context="http://www.springframework.org/schema/context"
6 xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
7 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
8 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
9
10 <context:component-scan base-package="com.proc"></context:component-scan>
11 <context:property-placeholder location="classpath:db.properties"/>
12 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
13 <property name="user" value="${jdbc.user}"></property>
14 <property name="password" value="${jdbc.password}"></property>
15 <property name="driverClass" value="${jdbc.driverClass}"></property>
16 <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
17 </bean>
18
19 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
20 <property name="dataSource" ref="dataSource"></property>
21 </bean>
22 </beans>
代码测试
1 UserDao userDao=(UserDao) ctx.getBean("userDao");
2 System.out.println(userDao.get(53));
标签：mysql tor odi mysq 实体 集合 属性 dao pac
原文地址：https://www.cnblogs.com/wang01/p/11783537.html
