使用MyBatis遇到的问题及解决方法(一)(持续更新)
这是一个出错的代码
1 public interface OrderInfoManageMapper { 2 List<GetOrderInfoManageListReq> selectAllOrder(); 3 void modifyDelivery(int id); 4 void removeOrder(int id); 5 List<GetOrderInfoManageListReq> selectOrderById(@Param("id") Integer id); 6 }
一、报错:
1 There is no getter for property named 'id' in 'class java.lang.Integer'
检查mapper.xml文件,没错,如下:
1 <select id="selectOrderById" parameterType="java.lang.Integer" resultMap="BaseResultMap"> 2 SELECT DISTINCT 3 order_info.id, 4 user_info.user_name, 5 order_info.order_status, 6 order_info.pay_type, 7 order_info.total_price, 8 ship_address.ship_user_name, 9 ship_address.ship_user_mobile, 10 ship_address.ship_address, 11 order_goods.goods_desc, 12 order_goods.goods_sku, 13 order_goods.goods_icon, 14 order_goods.goods_price 15 FROM 16 order_info, 17 user_info, 18 ship_address, 19 order_goods 20 WHERE 21 order_info.id = order_goods.order_id 22 AND order_info.user_id = user_info.id 23 AND order_info.ship_id = ship_address.id 24 <if test="id!= null and id!= '' "> 25 AND order_info.id = #{id} 26 </if> 27 </select>
检查mapper接口,如下:
1 public interface OrderInfoManageMapper { 2 List<GetOrderInfoManageListReq> selectAllOrder(); 3 void modifyDelivery(int id); 4 void removeOrder(int id); 5 List<GetOrderInfoManageListReq> selectOrderById(Integer id); 6 }
看似没有问题,但是id的话,需要这么写(看最后一行):
1 public interface OrderInfoManageMapper { 2 List<GetOrderInfoManageListReq> selectAllOrder(); 3 void modifyDelivery(int id); 4 void removeOrder(int id); 5 List<GetOrderInfoManageListReq> selectOrderById(@Param("id") Integer id); 6 }
二、sql没问题却报错:
java.sql.SQLException: 无效的列类型: 1111
原因是在mybatis中
1 SELECT 2 C_NAME1, 3 C_NAME2 4 FROM 5 MY_TABLE 6 WHERE 7 1=1 9 AND ID IN ({#param})
param是java传来的字符串 'id1','id2','id3'
此时就会报这个错误,因为使用in条件时不能用#,要使用$,如
1 SELECT 2 C_NAME1, 3 C_NAME2 4 FROM 5 MY_TABLE 6 WHERE 7 1=1 9 AND ID IN ({$param})
三、java想mybatis中传入‘a’,'b','c',放在in中
可能会这么写mybatis:
1 SELECT * FROM TABLE_NAME 2 WHERE 1=1 3 <if para!= null && para!="" > 4 AND PARS in (#{para}) 5 </if>
java传过来的para为
1 String para = "'a','x','d','g'";
此时预期效果为
1 SELECT * FROM TABLE_NAME 2 WHERE 1=1 3 AND PARS in ('a','x','d','g')
但是判断会通过,值不会传入,会出现:
1 SELECT * FROM TABLE_NAME 2 WHERE 1=1 3 AND PARS in ()
将#换成$才可以。虽然#很安全
1 SELECT * FROM TABLE_NAME 2 WHERE 1=1 3 <if para!=null && para!="" > 4 AND PARS in (${para}) 5 </if>
昔日我曾苍老,如今风华正茂(ง •̀_•́)ง