SpringBoot集成MyBatis

SpringBoot除了可以集成JPA，还可以集成MyBatis。

MyBatis专注于SQL本身，是一个足够灵活的DAO层解决方案。

对性能的要求很高，或者需求变化较多的项目，如互联网项目，MyBatis将是不错的选择。

1、注解

@Mapper
public interface UserMapper {

/**
* keyProperty: 表示将select返回值设置到该属性中
* resultType: 返回类型
* before: 是否在insert之前执行
* statement: 自定义子查询
* @param userBase
*/
@SelectKey(keyProperty = "userBase.id",resultType = String.class, before = true,
statement = "select replace(uuid(), '-', '')")
@Options(keyProperty = "userBase.id", useGeneratedKeys = true)
@Insert("insert into user_base(id, " +
"name, " +
"passwd, " +
"phone " +
") values (#{userBase.id}, " +
"#{userBase.name}, " +
"#{userBase.password}, " +
"#{userBase.phone}" +
") "
)
public void insertForReg(@Param("userBase")UserBase userBase);

@Delete("DELETE FROM user WHERE id =#{id}")
void delete(Long id);

}

简化了配置，也更符合Spring Boot的初衷。

2、配置文件

编写Mapper

@Mapper
public interface UserMapper {
    int insert(@Param("pojo") User pojo);

    int insertList(@Param("pojos") List<User> pojo);

    int update(@Param("pojo") User pojo);
}

编写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" >
<mapper namespace="com.wang.mybatis.UserMapper">

    <!--auto generated Code-->
    <resultMap id="AllColumnMap" type="com.wang.mybatis.User">
        <result column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="hobby" property="hobby"/>
    </resultMap>

    <!--auto generated Code-->
    <sql id="all_column">
        `id`,
        `name`,
        `hobby`
    </sql>

    <!--auto generated Code-->
    <insert id="insert">
        INSERT INTO `user`
        (`id`,`name`,`hobby`)
        VALUES (#{pojo.id},#{pojo.name},#{pojo.hobby})
    </insert>

    <!--auto generated Code-->
    <insert id="insertList">
        INSERT INTO `user`(
        <include refid="all_column"/>
        )VALUES
        <foreach collection="pojos" item="pojo" index="index" separator=",">
            (
            #{pojo.id},
            #{pojo.name},
            #{pojo.hobby}
            )
        </foreach>
    </insert>

    <!--auto generated Code-->
    <update id="update">
        UPDATE `user`
        <set>
            <if test="pojo.id != null"> `id` = #{pojo.id}, </if>
            <if test="pojo.name != null"> `name` = #{pojo.name}, </if>
            <if test="pojo.hobby != null"> `pwd` = #{pojo.hobby} </if>
        </set>
        WHERE `id` = #{pojo.id}
    </update>

</mapper>

配置

mybatis:
  mapper-locations: classpath*:mapper/*Mapper.xml
  type-aliases-package: com.wang.mybatis

总结：xml方式比较繁琐，可读性可维护性不强。自动化插件MyBatisCodeHelper可以帮助提高开发效率。