在Mybatis多条件查询中：
1.参数如果是多条件，则需要将将添加到Map集合中进行传入。
2.就是将其参数用有序数字进行代替。
mysql文如下，传入参数为‘parentCategoryId’，运行报错为：There is no getter for property named 'parentCategoryId' in 'class java.lang.String
<select id="selectCategoryList" parameterType="java.lang.String" resultType="MstCategoryBean">
SELECT category_id AS categoryId, category_name AS categoryName, view_orderby AS viewOrderby FROM mst_category WHERE del_flg =0 <if test="parentCategoryId!=null and parentCategoryId!=''"> and parent_category_id = #{parentCategoryId} </if> </select>
发现不能将参数设为bean里的名称，如果传入类型为String类型，则参数需统一修改为[_parameter],修改后的sql语句如下(不管你的参数是什么，都要改成"_parameter"
<select id="selectCategoryList" parametertype="java.lang.String" resulttype="MstCategoryBean">
SELECT category_id AS categoryId, category_name AS categoryName, view_orderby AS viewOrderby FROM mst_category WHERE del_flg =0 and parent_category_id = #{_parameter}
</select>