原文鏈接：http://blog.csdn.net/qq_22329521/article/details/75051031
導包
- 下載mybaits https://github.com/mybatis/mybatis-3/releases
- 下載連接mysql驅(qū)動
配置sqlMapconfig.xml文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 和spring整合后 environments配置將廢除 -->
<environments default="development">
<environment id="development">
<!-- 使用jdbc事務管理 -->
<transactionManager type="JDBC" />
<!-- 數(shù)據(jù)庫連接池 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url"
value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
<property name="username" value="root" />
<property name="password" value="" />
</dataSource>
</environment>
</environments>
<!--Mapper的位置,相當于每個對象的sql的映射文件-->
<mappers>
<mapper resource="sqlmap/User.xml"></mapper>
</mappers>
</configuration>
User.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--寫sql語句-->
<!--namespace命名空間姐浮，避免不同的mapper文件底下有同樣的id的sql方法-->
<mapper namespace="test">
<!--通過id查詢一個用戶-->
<select id="findUserById" parameterType="Integer" resultType="com.fmt.mybatis.pojo.User">
select * from user where id=#{v};
</select>
<!--
#{} 表示占位符()
${value} 表示字符串拼接
-->
<!--<select id="findUserByName" parameterType="String" resultType="com.fmt.mybatis.pojo.User">-->
<!--select * from user where username like '%${value}%';-->
<!--</select>-->
<!--防止sql注入-->
<select id="findUserByName" parameterType="String" resultType="com.fmt.mybatis.pojo.User">
select * from user where username like "%"#{v}"%";
</select>
<insert id="addUser" parameterType="com.fmt.mybatis.pojo.User">
<!-- 添加用戶返回調(diào)用獲取最后插入的id返回給用戶id-->
<selectKey keyProperty="id" resultType="Integer" order="AFTER">
select LAST_INSERT_ID()
</selectKey>
insert into user (username,birthday,address,sex) VALUE (#{username},#{birthday},#{address},#{sex})
</insert>
<update id="updateUserById" parameterType="com.fmt.mybatis.pojo.User">
update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address}
where id=#{id}
</update>
<delete id="deleteUserById" parameterType="Integer">
DELETE from user where id=#{id}
</delete>
</mapper>
增刪改查
@Test
public void fun1() throws IOException {
// 加載核心配置文件
String resource="sqlMapConfig.xml";
InputStream resourceAsStream = Resources.getResourceAsStream(resource);
//創(chuàng)建sqlSessionFactory
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(resourceAsStream);
//創(chuàng)建sqlsession
SqlSession sqlSession = factory.openSession();
/**
User o = sqlSession.selectOne("test.findUserById", 10);
System.out.println(o);
List<User> users=sqlSession.selectList("test.findUserByName","五");
for (User u:users){
System.out.println(u);
}
*/
/**
User user = new User();
user.setAddress("北京");
user.setSex("男");
user.setBirthday(new Date());
user.setUsername("富媒體");
int i= sqlSession.insert("test.addUser",user);
sqlSession.commit();
Integer id = user.getId();
System.out.println(id);
*/
/**
User user = new User();
user.setAddress("上海");
user.setSex("男");
user.setBirthday(new Date());
user.setUsername("富媒體");
user.setId(28);
int i= sqlSession.update("test.updateUserById",user);
sqlSession.commit();
*/
/*
int i= sqlSession.delete("test.deleteUserById",28);
sqlSession.commit();
*/
}
封裝dao調(diào)用getMapper方法
public interface UserMapper {
//遵循4個原則
//接口名字==User.xml中的id
//返回類型與Mapper.xml中的返回類型一直
//方法的入?yún)⑴cMapper.xml的入?yún)⒁恢? //命名空間綁定接口
List<User> findUserByQueryVo(QueryVo vo);
public Integer countUser();
}
<mapper namespace="com.fmt.mybatis.UserMapper">
<select id="findUserByQueryVo" parameterType="com.fmt.mybatis.pojo.QueryVo" resultType="com.fmt.mybatis.pojo.User">
select * from user where username like "%"#{user.username}"%";
</select>
<select id="countUser" resultType="Integer">
SELECT count(*) from USER
</select>
</mapper>
@Test
public void fun5() throws IOException {
// 加載核心配置文件
String resource="sqlMapConfig.xml";
InputStream resourceAsStream = Resources.getResourceAsStream(resource);
//創(chuàng)建sqlSessionFactory
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(resourceAsStream);
//創(chuàng)建sqlsession
SqlSession sqlSession = factory.openSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
QueryVo queryVo = new QueryVo();
User user = new User();
user.setUsername("五");
queryVo.setUser(user);
List<User> userByQueryVo = mapper.findUserByQueryVo(queryVo);
for (User u:userByQueryVo){
System.out.println(u);
}
System.out.println(mapper.countUser());
}
如果數(shù)據(jù)庫字段與對象中的字段不一致使用resultmap來處理
<resultMap id="orders" type="com.fmt.mybatis.pojo.Orders">
<!--數(shù)據(jù)庫字段與java對象中不同的字段映射-->
<result column="user_id" property="userId"/>
</resultMap>
<!--這里是resultMap 之前是resultType-->
<select id="selectOrderList" resultMap="orders">
SELECT id,user_id,number,createtime,note FROM orders
</select>
動態(tài)sql
- if/where
<!--where 標簽 可以去掉第一個前And-->
<select id="selectUserBySexAndUserName" parameterType="com.fmt.mybatis.pojo.User" resultType="com.fmt.mybatis.pojo.User">
select * from user
<where>
<if test="sex!=null and sex!=''">
sex=#{sex}
</if>
<if test="username!=null and username!=''">
and username =#{username}
</if>
</where>
</select>
別把and放后面 比如 username=#{username} and
User user = new User();
// user.setSex("1");
user.setUsername("張小明");
List<User> users = mapper.selectUserBySexAndUserName(user);
for (User or:users){
System.out.println(or);
}
- sql片段:提取公共是sql語句
<sql id="selector">
SELECT * FROM user
</sql>
<select id="selectuser" parameterType="com.fmt.mybatis.pojo.User" resultType="com.fmt.mybatis.pojo.User">
<include refid="selector"/>
<where>
<if test="sex!=null and sex!=''">
sex=#{sex}
</if>
<if test="username!=null and username!=''">
and username =#{username}
</if>
</where>
</select>
- foreach
<!--多個Id(1,2,3)-->
<!--<select id="selectUserByIds" parameterType="com.fmt.mybatis.pojo.QueryVo" resultType="com.fmt.mybatis.pojo.User">-->
<!--<include refid="selector"></include>-->
<!--<where>-->
<!--id IN -->
<!--<foreach collection="list_ids" item="id" separator="," open="(" close=")">-->
<!--#{id}-->
<!--</foreach>-->
<!--</where>-->
<!--</select>-->
<!--此處的array是傳入integer[]數(shù)組-->
<select id="selectUserByIds" parameterType="com.fmt.mybatis.pojo.QueryVo" resultType="com.fmt.mybatis.pojo.User">
<include refid="selector"></include>
<where>
id IN
<foreach collection="array" item="id" separator="," open="(" close=")">
#{id}
</foreach>
</where>
</select>
QueryVo queryVo = new QueryVo();
ArrayList<Integer> integers = new ArrayList<>();
integers.add(24);
integers.add(22);
queryVo.setList_ids(integers);
List<User> users = mapper.selectUserByIds(queryVo);
Integer[] integers=new Integer[2];
integers[0]=24;
integers[1]=22;
List<User> users = mapper.selectUserByIds(integers);
for (User or:users){
System.out.println(or);
}
一對一關(guān)聯(lián)
<!--一對一關(guān)聯(lián)-->
<resultMap type="com.fmt.mybatis.pojo.Orders" id="order">
<result column="id" property="id"/>
<result column="user_id" property="userId"/>
<result column="number" property="number"/>
<!-- 一對一 Order對象內(nèi)部有個user成員變量-->
<association property="user" javaType="com.fmt.mybatis.pojo.User">
<id column="user_id" property="id"/>
<result column="username" property="username"/>
</association>
</resultMap>
<select id="selectOrders" resultMap="order">
SELECT
o.id,
o.user_id,
o.number,
o.createtime,
u.username
FROM orders o
left join user u
on o.user_id = u.id
</select>
List<Orders> selectOrdersList = mapper.selectOrders();
for (Orders orders : selectOrdersList) {
System.out.println(orders);
}
一對多
<!--一對多-->
<resultMap type="com.fmt.mybatis.pojo.User" id="user">
<id column="user_id" property="id"/>
<result column="username" property="username"/>
<!-- 一對多用戶里面有訂單集合對象 -->
<collection property="ordersList" ofType="com.fmt.mybatis.pojo.Orders">
<id column="id" property="id"/>
<result column="number" property="number"/>
</collection>
</resultMap>
<select id="selectUserList" resultMap="user">
SELECT
o.id,
o.user_id,
o.number,
o.createtime,
u.username
FROM user u
left join orders o
on o.user_id = u.id
</select>
spring與mybatis結(jié)合
sqlMapConfig.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 設置別名 -->
<typeAliases>
<!-- 2. 指定掃描包，會把包內(nèi)所有的類都設置別名，別名的名稱就是類名坞古，大小寫不敏感 -->
<package name="com.fmt.springmybatis" />
</typeAliases>
<mappers>
<package name="com.fmt.springmybatis"/>
</mappers>
</configuration>
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<context:property-placeholder location="classpath:db.properties"/>
<!-- 數(shù)據(jù)庫連接池 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="10" />
<property name="maxIdle" value="5" />
</bean>
<!-- Mybatis的工廠 -->
<bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!-- 核心配置文件的位置 -->
<property name="configLocation" value="classpath:sqlMapConfig.xml"/>
</bean>
<!--原始dao-->
<!--<bean id="userDao" class="com.fmt.springmybatis.dao.UserDaoImp">-->
<!--<property name="sqlSessionFactory" ref="sqlSessionFactoryBean"></property>-->
<!--</bean>-->
<!--Mapper動態(tài)代理開發(fā)-->
<!--<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">-->
<!--<property name="sqlSessionFactory" ref="sqlSessionFactoryBean"></property>-->
<!--<property name="mapperInterface" value="com.fmt.springmybatis.map.UserMap"></property>-->
<!--</bean>-->
<!--Mapper掃描基本包 掃描-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!--基本包-->
<property name="basePackage" value="com.fmt.springmybatis.map"></property>
</bean>
</beans>
public class test {
@Test
public void test(){
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
//這是mapper動態(tài)代理
// UserMap userMapper = (UserMap) ac.getBean("userMapper");
//這是Mapper掃描基本包
UserMap userMap=ac.getBean(UserMap.class);
User userById = userMap.findUserById(10);
System.out.print(userById);
}
}
mybatis 逆向工程（mybaits需要程序員自己編寫sql語句,mybatis官方提供逆向工程,可以針對單表自動生成mybatis執(zhí)行所需要的代碼）
http://blog.csdn.net/h3243212/article/details/50778937
mybatis與hibernate的不同
Mybatis不完全是ORM框架伴找， 因為Mybatis需要程序員自己寫sql預計稻轨，程序員直接編寫原生態(tài)sql徒坡，可嚴格控制sql執(zhí)行性能羞酗，靈活度高，但是mybatis無法做到數(shù)據(jù)庫無關(guān)性（如果換數(shù)據(jù)庫sql需要重寫）无蜂，hibernate數(shù)據(jù)無關(guān)性強
別人總結(jié)很具體：http://www.cnblogs.com/inspurhaitian/p/4647485.html
