Question

我有一个更大的复杂查询的这一部分：

SELECT SUM(pir.priceChange) AS CASE 
WHEN (SUM(pir.priceChange) > 0) THEN sellSum 
WHEN (SUM(pir.priceChange) < 0) THEN priceSum 
END

每当我尝试通过PDO将其传递给MySQL（MyISAM）时，它会抛出异常：

语法错误或访问冲突：1064 SQL语法中出错;查看与您的MySQL服务器版本对应的手册，以便在'（SELECT SUM（pir.priceChange）AS CASE WHEN（SUM（pir.priceChange）＆gt; 0）THEN sellSu'第17行附近使用正确的语法

我想这与我试图错误地使用CASE语句这一事实有关。真的很想知道出了什么问题，提前谢谢。

编辑：我的完整查询（无任何情况编辑）：

SELECT  pi.id AS id,
pi.type AS type,
pi.parValue AS rating,
pi.duration AS time,
countAmt.amt AS amtSold,
IFNULL(pii.pChange,
0) AS priceTotal,
0) AS costTotal,
IFNULL(pii.selfPrice,
0) AS costPrice,
(IFNULL(pii.sellSum,
0) - IFNULL(pii.selfPrice,
0)) AS profit,
countClose.amtClosed AS amtClosed
FROM salon.paymentInstrument as pi
(SELECT SUM(pir.priceChange) AS pChange,
SUM(pir.costChange) AS cChange,
(IFNULL(pir.priceChange,
0) - IFNULL(pir.costChange,
0)) AS selfPrice,
pii.paymentInstrumentID
FROM salon.paymentInstrumentRegister as pir
JOIN salon.paymentInstrumentItem as pii ON pir.paymentInstrumentItemID = pii.id
WHERE pir.date >= '2014-04-11'
AND pir.date <= '2014-04-25'
GROUP BY pii.paymentInstrumentID 
) as pii
(SELECT pii.paymentInstrumentID,
COUNT(*) AS amtClosed
FROM salon.paymentInstrumentItem as pii
WHERE pii.annulTime >= 2014-04-11
AND pii.annulTime <= 2014-04-25
AND pii.status <> "active"
GROUP BY pii.paymentInstrumentID 
) as countClose
(SELECT pii.paymentInstrumentID,
COUNT(*) AS amt
FROM salon.paymentInstrumentItem as pii
WHERE pii.startTime >= 2014-04-11
AND pii.startTime <= 2014-04-25
GROUP BY pii.paymentInstrumentID 
) as countAmt

抱歉格式不正确，它是用PHP动态生成的。我有一种感觉，我在查询的其他地方犯了一个错误。

Answer 1

尝试这种方式：

SELECT CASE WHEN SUM(pir.priceChange)>0 THEN SUM(pir.priceChange) END as SumPrice,
       CASE WHEN SUM(pir.priceChange)<0 THEN SUM(pir.priceChange) END as priceSum
FROM TableName

SQL Fiddle中的示例。

Answer 2

试试这个：

SELECT CASE 
WHEN (SUM(pir.priceChange) > 0) THEN sellSum 
WHEN (SUM(pir.priceChange) < 0) THEN priceSum 
END

在SELECT中使用CASE的SQL查询不起作用

2 个答案: