如何对具有聚合函数的 Oracle 查询进行分组

Posted 2023-02-16

【中文标题】如何对具有聚合函数的 Oracle 查询进行分组

【英文标题】：how to group oracle queries which has aggregate functions

【发布时间】：2021-12-12 22:03:03

【问题描述】：

上面写着“不是 groupby 函数”。当我将 D.unitpricef 添加到 groupby 时，它没有显示任何错误，但结果它多次显示相同的 itmcode。一项代码应该只显示一次

SELECT 
    ItemCode, 
    case when H.InvoType = 1 then concat(ItemCode,' ( SLT Equipment )' ) else concat(ItemCode,' ( 
  CONBES Eqipment )' ) end as EquName,
    case when TRIM(SUM(QTY)) is null then ''  else TRIM(TO_CHAR(SUM(QTY),'999999')) end as QTY,
     CAST( (SUM(QTY) * D.unitpricef) AS NUMBER(38,2)) AS Amount
    FROM Invoicedetails D 
    INNER JOIN  
    invoiceheader H ON D.InvoiceNo = H.InvoiceNo 
    INNER JOIN Equipment E ON E.EquCode = ItemCode
    WHERE 
    H.CancelStat= 0 
    AND H.ReceiptStat = 1  
    AND H.BCCODE = 'xxx'
    GROUP BY ItemCode,H.InvoType ORDER BY ItemCode ASC;

【参考方案1】：

您需要使用与聚合函数关联的相同表达式来group by

SELECT 
    ItemCode, 
    case when H.InvoType = 1 then concat(ItemCode,' ( SLT Equipment )' ) else concat(ItemCode,' ( CONBES Eqipment )' ) end as EquName,
    case when TRIM(SUM(QTY)) is null then ''  else TRIM(TO_CHAR(SUM(QTY),'999999')) end as QTY,
    CAST( (SUM(QTY) * D.unitpricef) AS NUMBER(38,2)) AS Amount
    FROM Invoicedetails D 
    INNER JOIN  
    invoiceheader H ON D.InvoiceNo = H.InvoiceNo 
    INNER JOIN Equipment E ON E.EquCode = ItemCode
    WHERE 
    H.CancelStat= 0 
    AND H.ReceiptStat = 1  
    AND H.BCCODE = 'xxx'
    GROUP BY 
    ItemCode
    case when H.InvoType = 1 then concat(ItemCode,' ( SLT Equipment )' ) else concat(ItemCode,' ( CONBES Eqipment )' ) end 
  
    ORDER BY ItemCode ASC;

【讨论】：

我认为 case when TRIM(SUM(QTY)) is null then '' else TRIM(TO_CHAR(SUM(QTY),'999999')) end 不应该归入 group by 子句。

@AnkitBajpai，你是完全正确的。复制和粘贴时出现拼写错误；）谢谢