Mybatis_day02

SELECT
orders.*,
USER.username,
USER.sex,
USER.address
FROM
orders,
USER
WHERE orders.user_id = user.id

SELECT
orders.*,
USER.username,
USER.sex,
USER.address,
orderdetail.id orderdetail_id,
orderdetail.items_id,
orderdetail.items_num,
orderdetail.orders_id
FROM
orders,
USER,
orderdetail
WHERE orders.user_id = user.id
AND orders.id=orderdetail.orders_id

<!--定义resultMap：将订单查询结果的字段都封装到Orders对象中 -->
<resultMap type="cn.itcast.bean.Orders" id="BaseResultMap">
<!-- id：查询列表中的唯一标识，订单信息中的唯一标识，如果有多个Id，那么就定义多个ID
column:订单信息唯一标识列名(也就是数据库主键列名)
property:订单信息唯一标识映射到pojo的字段名 -->
<id column="id" property="id"/>
<!-- 定义普通属性查询列和pojo属性名之间的映射关系 -->
<result column="user_id" property="userId"/>
<result column="number" property="number"/>
<result column="createtime" property="createtime"/>
<result column="note" property="note"/>
<!-- 配置关联关系映射 -->
<!-- association: 配置一对一关联关系
property:要将关联查询映射到Orders中的那个属性
javaType:这是一对一中被关联的映射对象 -->
<association property="user" javaType="cn.itcast.bean.User">
<!-- id：关联查询用户的唯 一标识
column：指定唯 一标识用户信息的列
-->
<id column="user_id" property="id"/>
<result column="username" property="username"/>
<result column="sex" property="sex"/>
<result column="address" property="address"/>
</association>
<!-- 定义集合：一对多的关系
collection:对关联查询一对多的多条记录映射到集合对象中
property:定义要映射到Orders里面那个集合属性
ofType:需要被关联映射的对象-->
<collection property="orderList" ofType="cn.itcast.bean.Orderdetail">
<id column="orderdetail_id" property="id"/>
<result column="orders_id" property="ordersId"/>
<result column="items_id" property="itemsId"/>
<result column="items_num" property="items_num"/>
</collection>
</resultMap>

SELECT
orders.*,
USER.username,
USER.sex,
USER.address,
orderdetail.id orderdetail_id,
orderdetail.items_id,
orderdetail.items_num,
orderdetail.orders_id,
items.name items_name,
items.detail items_detail,
items.price items_price
FROM
orders,
USER,
orderdetail,
items
WHERE orders.user_id = user.id AND orderdetail.orders_id=orders.id AND orderdetail.items_id = items.id

<mapper namespace="cn.itcast.dao.UserMapper">
<!--需求：使用sql语句：select id id_,username _username from user
使用sql语句的别名来表示数据库的字段名，这个别名和javabean字段不相同
type:resultMap最终映射的java对象
id:标识resultMap的唯一标识
-->
<resultMap type="user" id="BaseResultMap">
<!-- 返回结果映射：id表示查询结果集中的唯一标识
column：查询出来的列名
property:查询出来映射的pojo的属性名
最终resultMap对象列名和javabean中属性进行一个映射
-->
<id column="id" property="id"/>
<!-- result：对普通列名进行定义
column：查询出来的列名
property:对应的javabean属性名 -->
<result column="username" property="username"/>
<result column="birthday" property="birthday"/>
<result column="sex" property="sex"/>
<result column="address" property="address"/>
<!-- 一个用户有多个订单
collection:集合，表示一个用户有多个订单
property:表示查询被关联到User中的属性

ofType:表示被关联属性类型-->
<collection property="ordersList" ofType="orders">
<id column="id" property="id"/>
<result column="user_id" property="userId"/>
<result column="number" property="number"/>
<result column="createtime" property="createtime"/>
<result column="note" property="note"/>
<!-- 订单中嵌套一层关系：一个订单有很多订单明细
集合中嵌套集合 -->
<collection property="detailList" ofType="orderdetail">
<id column="orderdetail_id" property="id"/>
<result column="orders_id" property="ordersId"/>
<result column="items_id" property="itemsId"/>
<result column="items_num" property="items_num"/>
<!-- 订单明细中包含：商品 -->
<association property="items" javaType="items">
<id column="id" property="id"/>
<result column="name" property="name"/>
<result column="price" property="price"/>
<result column="detail" property="detail"/>
<result column="pic" property="pic"/>
<result column="createtime" property="createtime"/>
</association>
</collection>
</collection>
</resultMap>

<!-- 延迟加载的resultMap -->
<resultMap type="cn.itcast.bean.Orders" id="OrdersUserLazyLoadingResultMap">
<!--对订单信息进行映射配置 -->
<id column="id" property="id"/>
<result column="user_id" property="userId"/>
<result column="number" property="number"/>
<result column="createtime" property="createtime"/>
<result column="note" property="note"/>

SELECT orders.*,
(SELECT username FROM USER WHERE orders.user_id = user.id)username,
(SELECT sex FROM USER WHERE orders.user_id = user.id)sex
FROM orders
-->
<association property="user" javaType="cn.itcast.bean.User"
select="cn.itcast.dao.UserMapper.findUserById" column="user_id">

<!-- 实现对用户信息进行延迟加载 -->
</association>
</resultMap>

<cachetype="org.mybatis.caches.ehcache.EhcacheCache">
<propertyname="timeToIdleSeconds"value="3600"/>
<propertyname="timeToLiveSeconds"value="3600"/>
<!-- 同ehcache参数maxElementsInMemory -->
<propertyname="maxEntriesLocalHeap"value="1000"/>
<!-- 同ehcache参数maxElementsOnDisk -->
<propertyname="maxEntriesLocalDisk"value="10000000"/>
<propertyname="memoryStoreEvictionPolicy"value="LRU"/>
</cache>

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">
<diskStore path="F:developehcache" />
<defaultCache
maxElementsInMemory="1000"
maxElementsOnDisk="10000000"
eternal="false"
overflowToDisk="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU">
</defaultCache>
</ehcache>

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd ">
<!-- 配置数据源 -->
<context:property-placeholder location="classpath:db.properties"/>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${jdbc.driver}"></property>
<property name="url" value="${jdbc.url}"></property>
<property name="username" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<!-- 配置工厂 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="configLocation" value="classpath:sqlMapConfig.xml"></property>
</bean>
<bean id="userDao" class="cn.itcast.dao.UserDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
<!-- 管理事务 -->
</beans>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<context id="testTables" targetRuntime="MyBatis3">
<commentGenerator>
<!-- 是否去除自动生成的注释 true：是 ： false:否 -->
<property name="suppressAllComments" value="true" />
</commentGenerator>
<!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/mybatis" userId="root"
password="mysql">
</jdbcConnection>
<!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver"
connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:yycg"
userId="yycg"
password="yycg">
</jdbcConnection> -->
<!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL 和
NUMERIC 类型解析为java.math.BigDecimal -->

<javaTypeResolver>
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- targetProject:生成PO类的位置 -->
<javaModelGenerator targetPackage="cn.itcast.ssm.po"
targetProject=".src">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
<!-- 从数据库返回的值被清理前后的空格 -->
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- targetProject:mapper映射文件生成的位置 -->
<sqlMapGenerator targetPackage="cn.itcast.ssm.mapper"
targetProject=".src">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
</sqlMapGenerator>
<!-- targetPackage：mapper接口生成的位置 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="cn.itcast.ssm.mapper"
targetProject=".src">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false" />
</javaClientGenerator>
<!-- 指定数据库表 -->
<table tableName="items"></table>
<table tableName="orders"></table>
<table tableName="orderdetail"></table>
<table tableName="user"></table>
</context>
</generatorConfiguration>

//自定义条件查询
@Test
publicvoid testSelectByExample() {
ItemsExample itemsExample = new ItemsExample();
//通过criteria构造查询条件
ItemsExample.Criteria criteria = itemsExample.createCriteria();
criteria.andNameEqualTo("笔记本3");
//可能返回多条记录
List<Items> list = itemsMapper.selectByExample(itemsExample);
System.out.println(list);
}
//根据主键查询
@Test
publicvoid testSelectByPrimaryKey() {
Items items = itemsMapper.selectByPrimaryKey(1);
System.out.println(items);
}
//插入
@Test
publicvoid testInsert() {
//构造 items对象
Items items = new Items();
items.setName("手机");
items.setPrice(999f);
itemsMapper.insert(items);
}
//更新数据
@Test
publicvoid testUpdateByPrimaryKey() {
//对所有字段进行更新，需要先查询出来再更新
Items items = itemsMapper.selectByPrimaryKey(1);
items.setName("水杯");
itemsMapper.updateByPrimaryKey(items);
//如果传入字段不空为才更新，在批量更新中使用此方法，不需要先查询再更新
//itemsMapper.updateByPrimaryKeySelective(record);
}