mySql更新案例无法正常工作

Question

在下面的查询中，前两个案例正在解决原因

UPDATE `FundCategory` SET `fundCategoryValue` = 
    CASE 
    WHEN `fundCategoryId` = '7' THEN fundCategoryValue + 700 
    WHEN `fundCategoryId` = '5' THEN fundCategoryValue - 700 
    WHEN `fundCategoryId` = '5' THEN fundCategoryValue + 700 
    WHEN `fundCategoryId` = '7' THEN fundCategoryValue - 700 

    ELSE `fundCategoryValue` 
    END
    WHERE `fundCategoryId` IN('7','5','5','7')

Answer 1

条件在前两个条件之后重复......并且case语句在找到工作条件时停止...所以最后两个不能工作。

Answer 2

你有两次相同的情况：

WHEN `fundCategoryId` = '7' THEN fundCategoryValue + 700 
WHEN `fundCategoryId` = '5' THEN fundCategoryValue - 700 
WHEN `fundCategoryId` = '5' THEN fundCategoryValue + 700 
WHEN `fundCategoryId` = '7' THEN fundCategoryValue - 700