Question

我是SQL的新手，我正试图从数据库中提取一些数据。

我有两张桌子，一张名为'tblorders'，另一张叫'tblorderitems'，我希望将这些表格加入团队订购的物品数量。

这是我创建的查询：

SELECT fldcustomerid, fldname, fldcontactname, fldemail, SUM(fldqtyorder) as QtyOrdered
FROM tblorders AS A
INNER JOIN tblorderitems AS B ON A.fldorderid = B.fldorderid
WHERE fldstockcode LIKE 'TO%' AND fldorderdate BETWEEN '2014-01-01' AND '2016-12-31'
AND fldemail LIKE '%@%' AND fldqtyorder>=30
GROUP BY fldname, fldcustomerid, fldcontactname, fldemail
ORDER BY QtyOrdered DESC

我希望它能够将'fldqtyorder'列中的项目数相加，然后过滤结果，以便只显示超过30个项目的结果。

例如，初始表将是：

fldname:     fldqtyorder:     fldcontactname:     fldemail:
TeamFC            24          Fred Jones          email@email1.com
FootyFC           1           Steve Low           Steeve@footy.com
TeamFC            16          James Wild          James@bt.com
Palm FC           33          Phil Bate           PBate@blah.com

最终结果应如下：

fldname:     fldtotalqtyorder:     fldcontactname:     fldemail:
TeamFC               40            Fred Jones          email@email1.com 
Palm FC              33            Phil Bate           PBate@blah.com

Answer 1

你想：

SELECT fldcustomerid, fldname, fldcontactname, fldemail, SUM(fldqtyorder) as QtyOrdered
FROM tblorders AS A
INNER JOIN tblorderitems AS B ON A.fldorderid = B.fldorderid
WHERE fldstockcode LIKE 'TO%' AND fldorderdate BETWEEN '2014-01-01' AND '2016-12-31'
AND fldemail LIKE '%@%'
GROUP BY fldname
HAVING QtyOrdered >= 30
ORDER BY QtyOrdered DESC

对于相同的fldname，您有不同的fldcontactnames，因此它将随机选择一个用于输出。与fldemail和fldcustomerid相同。但除此之外，输出应该是您正在寻找的。

您不能将额外的字段抛出到group by子句中，因为这会将组拆分为具有这些字段的唯一组合的每一行。如果您希望行具有相同的fldname时折叠为一行，则只有fldname可以在group by子句中。

Answer 2

这是一个操作问题的命令。

在where子句被评估时，它仅记录在单个记录上。通过将总和的评估移动到having子句，引擎将评估聚合并仅返回那些> = 30。

简单地从中删除＆gt; = 30并将其放入（不需要子查询）

SELECT fldcustomerid
     , fldname
     , fldcontactname
     , fldemail
     , SUM(fldqtyorder) as QtyOrdered
FROM tblorders AS A
INNER JOIN tblorderitems AS B 
  ON A.fldorderid = B.fldorderid
WHERE fldstockcode LIKE 'TO%' 
  AND fldorderdate BETWEEN '2014-01-01' AND '2016-12-31'
  AND fldemail LIKE '%@%' 
GROUP BY fldname, fldcustomerid, fldcontactname, fldemail
HAVING sum(fldqtyorder)>=30
ORDER BY QtyOrdered DESC

查询select语句的结果

2 个答案: