Mybatis传多个参数查询

一，用Map

Dao

public interface TopicUpdateDao {

	Topic selectByPrimaryKey(Integer id);

	List<Topic> selectNow(Map<String, Object> map);

}

Mapper

<select id="selectNow" resultMap="BaseResultMap" parameterType="java.util.Map">
		select
		<include refid="Base_Column_List" />
		from topic_update
		WHERE
		uptime = (SELECT MAX(uptime) FROM topic_update)
		ORDER BY rank
		LIMIT
		#{begin,jdbcType=INTEGER},#{size,jdbcType=INTEGER};
	</select>

 

        以前一直是用Map，忽然以为不太方便，我写的mapper，别人在service层调用我写的dao时不知道须要哪些参数，就查了一下有没有其余方法。

2、用@Param注解，这方法这样在调用dao层就知道须要哪些参数，很直观。

Dao

public interface TopicUpdateDao {

	Topic selectByPrimaryKey(Integer id);

	List<Topic> selectNow(@Param("begin") Integer begin, @Param("size") Integer size);

}

Mapper.xml

<select id="selectNow" resultMap="BaseResultMap">
		select
		<include refid="Base_Column_List" />
		from topic_update
		WHERE
		uptime = (SELECT MAX(uptime) FROM topic_update)
		ORDER BY rank
		LIMIT
		#{begin,jdbcType=INTEGER},#{size,jdbcType=INTEGER};
	</select>

3、占位，dao层和上面同样多个参数，mapper用#{x}表示第几个参数，第一个是0，类推。

<select id="selectNow" resultMap="BaseResultMap">
		select
		<include refid="Base_Column_List" />
		from topic_update
		WHERE
		uptime = (SELECT MAX(uptime) FROM topic_update)
		ORDER BY rank
		LIMIT
		#{0},#{1};
	</select>

这个方法不太直观。