Question

我在MySql服务器上运行的查询有问题。这是查询：

SELECT itms.Gender,itms.Age, (CASE WHEN (plv.Discount = 0 OR t1.EverGreen = 1) THEN 'A' ELSE 'S' END) as SCode, itms.SubLineID, min(t1.DayDelivery)
FROM item as t1 
INNER JOIN item_contest_summary as itms 
    on (t1.SeasonID=itms.SeasonID and t1.CollectionID=itms.CollectionID and t1.ItemID=itms.ItemID and itms.JoinType<2) 
INNER JOIN pricelist_summary as plc 
    on (plc.CountryID = 'IT' AND plc.SeasonID = itms.PriceSeasonID AND plc.CollectionID = itms.PriceCollectionID AND plc.ItemID = itms.PriceItemID ) 
INNER JOIN pricelist AS plv 
    on (plv.ListCode = plc.ListCode AND plv.SeasonID = itms.PriceSeasonID AND plv.CollectionID = itms.PriceCollectionID AND plv.ItemID = itms.PriceItemID AND (plv.ListPrice > 0 or itms.IsGAG))    
WHERE itms.SCode IN ('S', 'A') AND itms.Age in ('A','K','') AND t1.HasPrivateSale = 0 AND itms.ExclLista = 0 AND itms.IsGAG = 0 
GROUP BY itms.Gender,itms.Age, 
(CASE WHEN (plv.Discount = 0 OR t1.EverGreen = 1) THEN 'A' ELSE 'S' END), 
itms.SubLineID

当我们在服务器上禁用严格的sql（在版本5.1中）时，该语句工作正常，然后我们将系统升级到5.6，启用严格的sql模式，这里出现问题。这个查询的问题似乎是部分时的表达式：

(plv.Discount = 0 OR t1.EverGreen = 1)

在OR中只使用其中一个表达式，一切正常（两者都留下第一个和第二个表达式）。似乎不可能在case when子句使用的表达式中使用任何AND / OR / etc。为什么？有没有其他方法可以编写这种查询？

编辑：

这是我得到的错误：

错误代码：1055。＆＃39; plv.Discount＆＃39;不在GROUP BY

Answer 1

我发现使用别名进行分组非常有效。因此，工作查询是：

SELECT itms.Gender,itms.Age, 
    (CASE WHEN (plv.Discount = 0 OR t1.EverGreen = 1) THEN 'A' ELSE 'S' END) as SCode, 
    itms.SubLineID , min(t1.DayDelivery)
FROM item as t1 
INNER JOIN item_contest_summary as itms 
    on (t1.SeasonID=itms.SeasonID and t1.CollectionID=itms.CollectionID and t1.ItemID=itms.ItemID and itms.JoinType<2) 
INNER JOIN pricelist_summary as plc 
    on (plc.CountryID = 'IT' AND plc.SeasonID = itms.PriceSeasonID AND plc.CollectionID = itms.PriceCollectionID AND plc.ItemID = itms.PriceItemID ) 
INNER JOIN pricelist AS plv 
    on (plv.ListCode = plc.ListCode AND plv.SeasonID = itms.PriceSeasonID AND plv.CollectionID = itms.PriceCollectionID AND plv.ItemID = itms.PriceItemID AND (plv.ListPrice > 0 or itms.IsGAG))    
WHERE itms.SCode IN ('S', 'A') AND itms.Age in ('A','K','') AND t1.HasPrivateSale = 0 AND itms.ExclLista = 0 AND itms.IsGAG = 0 
GROUP BY itms.Gender,itms.Age, 
    SCode, 
    itms.SubLineID

我仍然不明白为什么只有在 case 语句中使用复杂表达式时才需要这样做。此外，即使没有选择上的聚合功能，此版本的查询仍然有效。解决了这个问题，但仍然困惑......

在没有在mysql 5.6严格的sql模式下工作的情况下分组

编辑：

1 个答案: