Question

我不能在CASE语句中使用MySQL别名，它会产生如下语法错误：

SELECT IFNULL(min(mFR.date),'') AS `firstDate`,
    CASE `data` 
        WHEN 'Sales'         THEN IFNULL(SUM(qty),0) AS `sales`
        WHEN 'Return'        THEN IFNULL(SUM(qty),0) AS `return`
        WHEN 'Receiving In'  THEN IFNULL(SUM(qty),0) AS `receiving_in`
        WHEN 'Receiving Out' THEN IFNULL(SUM(qty),0) AS `receiving_out`
        WHEN 'Stock'         THEN IFNULL(SUM(qty),0) AS `stock`
    END
FROM  `full_report`

它给了我（[AS sales]附近的语法错误）。

有什么建议吗？

Answer 1

您正尝试为案例的每个分支使用别名，这是不可能的。

我认为您想使用单独的案例：

SELECT IFNULL(min(mFR.date),'') AS `firstDate`
    ,sum(CASE `data` WHEN 'Sales'         THEN qty END) AS `sales`
    ,sum(CASE `data` WHEN 'Return'        THEN qty END) AS `return`
    ,sum(CASE `data` WHEN 'Receiving In'  THEN qty END) AS `receiving_in`
    ,sum(CASE `data` WHEN 'Receiving Out' THEN qty END) AS `receiving_out`
    ,sum(CASE `data` WHEN 'Stock'         THEN qty END) AS `stock`
FROM  `full_report`

之后使用MySQL别名和case语句

1 个答案: