Question

我想问一下是否有办法修改我的SQL Select语句以防止冗余行，如下所示。

SELECT tblIssueCommsItem.ItemID, cardNo, tblIssueCommsEqp.currentQty FROM tblIssueCommsItem 
INNER JOIN tblCommsItem ON tblIssueCommsItem.ItemID = tblCommsItem.ItemID 
INNER JOIN tblIssueCommsEqp ON tblIssueCommsItem.EqpID = tblIssueCommsEqp.EqpID  
INNER JOIN tblSetInfo ON tblSetInfo.EqpID = tblIssueCommsEqp.EqpID 
WHERE SetID = 11 AND (cardNo = 'TK 14' OR cardNo = '') AND cardNo != 'Unassigned' 
AND tblIssueCommsItem.VoucherNo = 10006102 AND tblIssueCommsEqp.currentQty > 0
ORDER BY cardNo, serial

我得到了什么：

ItemID: 1386, cardNO: *blank*, currentQty: 10
ItemID: 1386, cardNO: *blank*, currentQty: 1
ItemID: 1387, cardNO: *blank*, currentQty: 10
ItemID: 1387, cardNO: *blank*, currentQty: 1
ItemID: 1101, cardNO: TK 14, currentQty: 10
ItemID: 1101, cardNO: TK 14, currentQty: 1
ItemID: 2575, cardNO: TK 14, currentQty: 10
ItemID: 2575, cardNO: TK 14, currentQty: 1

SetInfo包含属于集合的不同EqpIDs。在这种情况下，集合为SetID 11.我想要实现的目标如下：

ItemID: 1386, cardNO: *blank*, currentQty: 10
ItemID: 1387, cardNO: *blank*, currentQty: 10
ItemID: 1101, cardNO: TK 14, currentQty: 10
ItemID: 2575, cardNO: TK 14, currentQty: 10

我意识到冗余行只发生在我在cardNO = 'TK 14'集合中有多个项目时。如您所见，冗余行是currentQty = 1的行。我的数据库中没有这样的记录。我认为它只显示为1，因为它是int字段。 currentQty不同，这些不是真正重复的行，因此我无法使用DISTINCT来摆脱它。

我对JOIN的概念并不好，但我尝试了各种JOIN，它会产生完全相同的结果。

任何帮助表示赞赏！

更新：解决了问题。感谢那些澄清不提供默认整数的SQL行为的人。 tblIssueCommsEqp.*，帮助我识别罪魁祸首，并意识到我需要tblIssueCommsEqp.VoucherNo = 10000602 and tblIssueCommsItem.VoucherNo = 1000602来获得我想要的东西。

由于我的概念仍然很弱，我仍然不确定为什么如果我在一组中只有1项“TK 14”，那么一切都按照正常情况运作。

对于有助于修改我的陈述的答案，这些可能也有用，但它们有点作弊，我只会将它作为最后的手段。

Answer 1

假设SQL Server，例如：

 group by tblIssueCommsItem.ItemID, cardNo, tblIssueCommsEqp.currentQty
 having max(tblIssueCommsEqp.currentQty)

不确定是否适用于订单，但希望能让您朝着正确的方向前进：）

Answer 2

我想你想要：

SELECT
  tblIssueCommsItem.ItemID,
  cardNo,
  MAX(tblIssueCommsEqp.currentQty)
FROM
  tblIssueCommsItem
  INNER JOIN tblCommsItem
    ON tblIssueCommsItem.ItemID = tblCommsItem.ItemID
  INNER JOIN tblIssueCommsEqp
    ON tblIssueCommsItem.EqpID = tblIssueCommsEqp.EqpID
  INNER JOIN tblSetInfo
    ON tblSetInfo.EqpID = tblIssueCommsEqp.EqpID
WHERE
  SetID = 11
  AND (
        cardNo = 'TK 14'
        OR cardNo = ''
      )
  AND cardNo != 'Unassigned'
  AND tblIssueCommsItem.VoucherNo = 100006102
  AND tblIssueCommsEqp.currentQty > 0
GROUP BY  
  tblIssueCommsItem.ItemID,
  cardNo
ORDER BY
  cardNo

Answer 3

试试这个：

SELECT tblIssueCommsItem.ItemID, cardNo, q.currentQty 
FROM tblIssueCommsItem 
INNER JOIN tblCommsItem ON tblIssueCommsItem.ItemID = tblCommsItem.ItemID 
INNER JOIN 
(
    select EqpID, MAX(currentQty) as currentQty
    from tblIssueCommsEqp 
    group by EqpID
    having max(currentQty) > 0
) q ON tblIssueCommsItem.EqpID = q.EqpID  
INNER JOIN tblSetInfo ON tblSetInfo.EqpID = tblIssueCommsEqp.EqpID 
WHERE SetID = 11 AND (cardNo = 'TK 14' OR cardNo = '') 
    AND tblIssueCommsItem.VoucherNo = 100006102
    -- The below line is redundant, though it may still be useful in matching an index
    -- AND cardNo != 'Unassigned'   
ORDER BY cardNo, serial

Answer 4

这可能会有所帮助。我认为包含 max function 会有所帮助，因为你包含了 max 内置函数，所以删除 tblIssueCommsEqp.currentQty＆gt; where子句中的0条件。

SELECT tblIssueCommsItem.ItemID, cardNo, Max(tblIssueCommsEqp.currentQty) 
FROM tblIssueCommsItem 
INNER JOIN tblCommsItem ON tblIssueCommsItem.ItemID = tblCommsItem.ItemID 
INNER JOIN tblIssueCommsEqp ON tblIssueCommsItem.EqpID = tblIssueCommsEqp.EqpID  
INNER JOIN tblSetInfo ON tblSetInfo.EqpID = tblIssueCommsEqp.EqpID 
WHERE SetID = 11 
AND (cardNo = 'TK 14' OR cardNo = '') 
AND cardNo != 'Unassigned' 
AND tblIssueCommsItem.VoucherNo = 100006102 
ORDER BY cardNo, serial;

SQL中的冗余行选择“加入”

4 个答案: