Question

我正在使用IBM Cognos创建一个报告，该报告允许使用相当标准的SQL。我最终尝试从2个表中获取数据，并将它们相互比较以确保它们匹配。在比较t1和t3之间的给定Contract_Number，Contract_Item和Stream_Type时，Billing_Term，Bill_Period和Contract_Term_Amount都需要匹配，但仅限于t3中的MAX Seq_No。

我在Seq_No上尝试了一个简单的MAX（），但是那没有用，因此我正在寻求帮助，以将相关查询结果的结果限制为MAX Seq_No。



    SELECT
        t1.Contract_Number, 
        t1.Contract_Item, 
        t1.Stream_Type, 
        t1.Billing_Term, 
        t1.Bill_Period, 
        t1.Contract_Term_Amount,
        t2.Reference_Document,
        t3.Billing_Term,
        t3.Bill_Period,
        t3.Contract_Term_Amount,
        t3.Seq_No
    FROM
        LeasingStreamData t1 
    INNER JOIN ContractsData t2 ON t1.Contract_Number = t2.Sales_Document
    LEFT JOIN LeasingStreamData t3 ON t2.Reference_Document = t3.Contract_Number AND
        t1.Contract_Item = t3.Contract_Item AND
        t1.Stream_Type = t3.Stream_Type
    WHERE 
    t1.Contract_Number IN ([some list of contracts])
    GROUP BY 
        t1.Contract_Number, 
        t1.Contract_Item, 
        t1.Stream_Type, 
        t1.Billing_Term, 
        t1.Bill_Period, 
        t1.Contract_Term_Amount,
        t2.Reference_Document,
        t3.Billing_Term,
        t3.Bill_Period,
        t3.Contract_Term_Amount,
        t3.Seq_No

我希望这足以获得一些急需的帮助，非常感谢您能提供的任何帮助！

Answer 1

If I understand you requirement, I think you want to create queries and join them in a way that will look like this SQL:

SELECT
  t1.Contract_Number
, t1.Contract_Item
, t1.Stream_Type
, t1.Billing_Term
, t1.Bill_Period
, t1.Contract_Term_Amount
, t2.Reference_Document
, t3.Billing_Term
, t3.Bill_Period
, t3.Contract_Term_Amount
, t3.Seq_No

FROM (
    SELECT Contract_Number
    , Contract_Item
    , Stream_Type
    , Billing_Term
    , Bill_Period
    , Contract_Term_Amount
    FROM LeasingStreamData
    WHERE Contract_Number in ([some list of contracts])
  ) t1 
  INNER JOIN (
    SELECT Sales_Document
    , Reference_Document
    FROM ContractsData
    WHERE Sales_Document in ([some list of contracts])
  ) t2 ON t1.Contract_Number = t2.Sales_Document
  INNER JOIN LeasingStreamData t3 ON t2.Reference_Document = t3.Contract_Number 
                               AND t1.Contract_Item = t3.Contract_Item 
                               AND t1.Stream_Type = t3.Stream_Type
  INNER JOIN (
      select max(Seq_No) as Seq_No
      , Contract_Number
      , Contract_Item
      , Stream_Type
      from LeasingStreamData lsd
      group by Contract_Number
      , Contract_Item
      , Stream_Type
  ) maxseq on maxseq.Contract_Number = t3.Contract_Number
          and maxseq.Contract Item = t3.Contract_Item
          and maxseq.Stream_Type = t3.Stream_Type
          and maxseq.Seq_No = t3.Seq_No

WHERE t1.Billing_Term <> t3.Billing_Term
  and t1.Bill_Period <> t3.Bill_Period
  and t1.Contract_Term_Amount <> t3.Contract_Term_Amount

GROUP BY 
  t1.Contract_Number
, t1.Contract_Item
, t1.Stream_Type
, t1.Billing_Term
, t1.Bill_Period
, t1.Contract_Term_Amount
, t2.Reference_Document
, t3.Billing_Term
, t3.Bill_Period
, t3.Contract_Term_Amount
, t3.Seq_No

I think this will filter to only the max Seq_No for t3 and return only the records that you care about (the ones that don't match).

Answer 2

尝试一下：

SELECT t1.Contract_Number
    ,t1.Contract_Item
    ,t1.Stream_Type
    ,t1.Billing_Term
    ,t1.Bill_Period
    ,t1.Contract_Term_Amount
    ,t2.Reference_Document
    ,t3.Billing_Term
    ,t3.Bill_Period
    ,t3.Contract_Term_Amount
    ,t3.Seq_No
FROM LeasingStreamData t1
INNER JOIN ContractsData t2 ON t1.Contract_Number = t2.Sales_Document
LEFT JOIN (
    SELECT Contract_Number
        ,Contract_Item
        ,Stream_type
        ,MAX(Seq_No) AS "Seq_No"
    FROM LeasingStreamData
    GROUP BY Contract_Number
        ,Contract_Item
        ,Stream_Type
    ) t3 ON t2.Reference_Document = t3.Contract_Number
    AND t1.Contract_Item = t3.Contract_Item
    AND t1.Stream_Type = t3.Stream_Type
WHERE t1.Contract_Number IN ([some list of contracts])

由于汇总函数（MAX）的汇总取决于分组依据来确定上下文，因此在连接其余表之前，您必须通过子查询将其隔离以获取最大值。

此外，由于您正在预先汇总最大序列号，因此在主查询中不再需要分组依据。

SQL选择多个联接和MAX（字段）结果

2 个答案: