mybatis整合spring boot

1. 在pom.xml加入如下内容

   <dependency>
       <groupId>org.mybatis.spring.boot</groupId>
       <artifactId>mybatis-spring-boot-starter</artifactId>
       <version>1.3.0</version>
   </dependency>

2. mybatis-config.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>
       <typeAliases>
           <typeAlias alias="Integer" type="java.lang.Integer"/>
           <typeAlias alias="Long" type="java.lang.Long"/>
           <typeAlias alias="HashMap" type="java.util.HashMap"/>
           <typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap"/>
           <typeAlias alias="ArrayList" type="java.util.ArrayList"/>
           <typeAlias alias="LinkedList" type="java.util.LinkedList"/>
       </typeAliases>
       <typeAliases>
           <package name="top.ylonline.wechat.job.pojo"/>
       </typeAliases>
       <mappers>
           <mapper resource="top/ylonline/wechat/job/mapper/UserMapper.xml"/>
       </mappers>
   </configuration>

或者在application.yml中加入

mybatis:
  config-location: classpath:mybatis/mybatis-config.xml
  type-aliases-package: top.ylonline.wechat.job.pojo
#  mapper-locations 这个配置参数仅当mapper xml与mapper class不在同一个目录下时有效。所以一般可以忽略。
#  mapper-locations: classpath:top/ylonline/wechat/job/mapper/*.xml

在Mapper类上面使用 @Mapper 注解

@Mapper
public interface UserMapper {
    long count(User user);
}

Mapper.xml配置

<?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" >
<mapper namespace="top.ylonline.wechat.job.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="top.ylonline.wechat.job.pojo.User">
        <constructor>
            <arg column="ID" javaType="java.math.BigDecimal" jdbcType="DECIMAL"/>
            <arg column="AGE" javaType="java.math.BigDecimal" jdbcType="DECIMAL"/>
            <arg column="CITYID" javaType="java.math.BigDecimal" jdbcType="DECIMAL"/>
        </constructor>
    </resultMap>

    <select id="count" parameterType="top.ylonline.wechat.job.pojo.User" resultType="java.lang.Long">
        select count(*) from user where cityid = #{user.cityid}
    </select>
</mapper>