Mybatis IN操作

其中collection 为 mapper里面的param("")里面的参数 遍历的单个对象 为item的值,当查询的参数有多个时,有两种方式可以实现，一种是使用@Param("xxx")进行参数绑定，另一种可以通过Map来传参数。

List<User> selectByIdSet(@Param("name")String name, @Param("ids")String[] idList);
 
<select id="selectByIdSet" resultMap="BaseResultMap">
	SELECT
	<include refid="Base_Column_List" />
	from t_user
	WHERE  name=#{name,jdbcType=VARCHAR} and id IN
	<foreach collection="ids" item="id" index="index"
			 open="(" close=")" separator=",">
	  #{id}
	</foreach>

Map传参

Map<String, Object> params = new HashMap<String, Object>(2);
params.put("name", name);
params.put("idList", ids);
mapper.selectByIdSet(params);
<select id="selectByIdSet" resultMap="BaseResultMap">  
     select  
     <include refid="Base_Column_List" />  
     from t_user where 
     name = #{name}
     and ID in  
     <foreach item="item" index="index" collection="idList" open="(" separator="," close=")">  
      #{item}  
     </foreach>  

如果参数的类型是Array,则在使用时，collection属性要必须指定为 array

List<User> selectByIdSet(String[] idList);
 
<select id="selectByIdSet" resultMap="BaseResultMap">
	SELECT
	<include refid="Base_Column_List" />
	from t_user
	WHERE id IN
	<foreach collection="array" item="id" index="index" open="(" close=")" separator=",">
	  #{id}
	</foreach>
</select>

单个参数时 如果参数的类型是List, 则在使用时，collection属性要必须指定为 list

List<User> selectByIdSet(List idList);
 
<select id="selectByIdSet" resultMap="BaseResultMap">
	SELECT
	<include refid="Base_Column_List" />
	from t_user
	WHERE id IN
	<foreach collection="list" item="id" index="index" open="(" close=")" separator=",">
	  #{id}
	</foreach>
</select>

Mybatis IN操作

原文：https://www.cnblogs.com/braless/p/14605341.html