删除 SQL 中的重复项答案

【问题标题】：Removing Duplicates in SQL删除 SQL 中的重复项
【发布时间】：2017-11-17 05:46:56
【问题描述】：

我需要选择所有尚未开票的订单 and BR.isInvoiced = 0

Select DG.DateGenerated, oit.OrderIdentifier, BR.isInvoiced, BR.hash, BR.OrderNumber, UL.FirstName, UL.LastName from [Order] O INNER JOIN BillingReport BR ON O.OrderNumber = BR.OrderNumber INNER JOIN UsersLib UL ON UL.UserID = O.UserId INNER JOIN Order_Identifier_Transactional OIT ON O.OrderNumber = OIT.OrderNumber INNER JOIN (Select OP.OrderNumber, OP.DateGenerated from OrderProducts OP group by OP.OrderNumber, op.DateGenerated having op.DateGenerated in (select MAX(op.DateGenerated) from orderproducts ))as DG ON DG.OrderNumber = O.OrderNumber where O.Status = 'COMPLETED' and BR.isInvoiced = 0 and UL.UserName not like '%Support%' and UL.AccountNumber != '10000001001' and BR.invoicepdf is NULL and BR.ispaid = 0

然后只选择每个订单号生成的最近日期但使用这个查询我仍然发现一些像这样的重复：

【问题讨论】：

如果您仔细观察，您会发现这两个突出显示的记录的 DateGenerated 并不相同。因此，它们在技术上是不同的记录，而不是重复的。
是的。但我们正在寻找最近生成的日期。如附图所示

标签： sql sql-server duplicates inner-join having

【解决方案1】：

这是解决问题的最快方法：

SELECT MAX(DateGenerated), OrderIdentifier, isInvoiced, hash, OrderNumber, 
    FirstName, LastName
FROM (Select DG.DateGenerated, oit.OrderIdentifier, BR.isInvoiced, BR.hash, 
    BR.OrderNumber, UL.FirstName, UL.LastName   from [Order] O
    INNER JOIN BillingReport BR
    ON O.OrderNumber = BR.OrderNumber
    INNER JOIN UsersLib UL
    ON UL.UserID = O.UserId
    INNER JOIN Order_Identifier_Transactional OIT
    ON O.OrderNumber = OIT.OrderNumber
    INNER JOIN
     (Select OP.OrderNumber, OP.DateGenerated from OrderProducts OP 
     group by OP.OrderNumber, op.DateGenerated
      having op.DateGenerated in (select MAX(op.DateGenerated) from orderproducts ))as DG
    ON DG.OrderNumber = O.OrderNumber
    where O.Status = 'COMPLETED' 
    and BR.isInvoiced = 0
    and UL.UserName not like '%Support%' 
    and UL.AccountNumber != '10000001001' 
    and BR.invoicepdf is NULL 
    and BR.ispaid = 0)
GROUP BY OrderIdentifier, isInvoiced, hash, OrderNumber, FirstName, LastName

我获取了您的整个查询，将其用引号括起来，然后使用围绕 DateGenerated 的 MAX 聚合函数从中选择。最后，我为所有其他字段添加了 GROUP BY 子句。

【讨论】：

重复我们仍然出现。
这段代码现在可以工作了，但是我在括号和BR.ispaid = 0) as OA 的末尾加上了一个别名，代码就可以工作了。谢谢大家的帮助，谢谢大家

【解决方案2】：

你的 MAX 选择中有一个别名

(select MAX(op.DateGenerated) from orderproducts )

试试这个：

(select MAX(DateGenerated) from orderproducts where ordernumber = op.ordernumber )

【讨论】：

【解决方案3】：

您是否尝试过在第二个INNER JOIN 上使用UNIQUE？

INNER JOIN
     (Select UNIQUE OP.OrderNumber, OP.DateGenerated
      from OrderProducts OP 
      group by OP.OrderNumber, op.DateGenerated
      having op.DateGenerated in
            (select MAX(op.DateGenerated)
             from orderproducts )) as DG
ON DG.OrderNumber = O.OrderNumber

【讨论】：

尝试唯一码时也会出现重复

【解决方案4】：

Select DG.DateGenerated, oit.OrderIdentifier, BR.isInvoiced, BR.hash, 
    BR.OrderNumber, UL.FirstName, UL.LastName   from [Order] O
    INNER JOIN BillingReport BR
    ON O.OrderNumber = BR.OrderNumber
    INNER JOIN UsersLib UL
    ON UL.UserID = O.UserId
    INNER JOIN Order_Identifier_Transactional OIT
    ON O.OrderNumber = OIT.OrderNumber
    INNER JOIN
     (Select OP.OrderNumber, OP.DateGenerated from OrderProducts OP 
     group by OP.OrderNumber, op.DateGenerated
      having op.DateGenerated in (select MAX(op.DateGenerated) from orderproducts OP1 WHERE OP.OrderNumber =  OP1.OrderNumber))as DG
    ON DG.OrderNumber = O.OrderNumber
    where O.Status = 'COMPLETED' 
    and BR.isInvoiced = 0
    and UL.UserName not like '%Support%' 
    and UL.AccountNumber != '10000001001' 
    and BR.invoicepdf is NULL 
    and BR.ispaid = 0

您在找到最近生成的日期时缺少WHERE OP.OrderNumber = OP1.OrderNumber。希望对你有帮助。

【讨论】：