>Mybatis CASE WHEN 的用法

Case具有两种格式。简单Case函数和Case搜索函数。
简单Case函数
CASE sex
WHEN ‘1’ THEN ‘男’
WHEN ‘2’ THEN ‘女’
ELSE ‘其他’ END

–Case搜索函数
CASE WHEN sex = ‘1’ THEN ‘男’
WHEN sex = ‘2’ THEN ‘女’
ELSE ‘其他’ END
两 种方式，可以实现相同的功能。简单Case函数的写法相对比较简洁，但是和Case搜索函数相比，功能方面会有些限制，比如写判断式。还有一个需要注意的问题，Case函数只返回第一个符合条件的值，剩下的Case部分将会被自动忽略。
–比如说，下面这段SQL，你永远无法得到“第二类”这个结果
CASE WHEN col_1 IN ( ‘a’, ‘b’) THEN ‘第一类’
WHEN col_1 IN (‘a’) THEN ‘第二类’
ELSE’其他’ END

注意: 改完sql,也要改返回值类型呀,不然会报如下错误

对应不上字段,查是能查了,但是匹配字段的时候报错!!!

ERROR 5596 --- [nio-9099-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: Error attempting to get column 'push_manner' from result set.  Cause: java.sql.SQLDataException: Cannot determine value type from string '站内信'
; Cannot determine value type from string '站内信'; nested exception is java.sql.SQLDataException: Cannot determine value type from string '站内信'] with root cause

com.mysql.cj.exceptions.DataConversionException: Cannot determine value type from string '站内信'

实例:

    <select id="getOutStockApply" parameterType="com.boot.reservation.entity.domain.qo.OutStockQO"
            resultType="com.boot.reservation.entity.outstock.OutStockApplyDTO">
            select
            id,
            apply_out_stock_serial_num applyOutStockSerialNum,
            granary_address granaryAddress,
            goods_name goodsName,
            usable_num usableNum,
            goods_level goodsLevel,
            out_num outNum,
            out_date outDate,
            outter_name outterName,
            outter_tel outterTel,
            outter_id outterId,
            out_remark outRemark,
            ( CASE
                            WHEN STATUS = '00' THEN '已保存'
                            WHEN STATUS = '01' THEN '待审核'
                            WHEN STATUS = '02' THEN '已通过'
                            WHEN STATUS = '03' THEN '已驳回'
                          END )	status,
            file_id fileId,
            pic_id picId
            from
            storage_out_stock_apply
            where
            apply_out_stock_serial_num =#{applyOutStockSerialNum}
    </select>