在 MERGE SQL 查询中遇到问题

Question

我有一个要求，insert/update 从暂存 table stgTbl 到另一个 table T2 的数据。如果存在更新，无论有多少重复项。同样，如果不存在，直接插入T2。很简单的。由于暂存 table stgTb1 是每天的预定工作。有时我也会得到多个重复的行。因此，由于重复，合并语句产生错误：

"The MERGE statement attempted to UPDATE or DELETE the same row more than once. This happens when a target row matches more than one source row".

我尝试使用校验和，但仍然得到，因为我可能在校验和中做错了。 table 中都没有主键（我删除了，否则我会收到主键约束错误）。基于列（帐户和 ref_key2）应与 insert/update 一起使用。我已经尝试过 if else with exists also 但不知何故，如果目标 table T2 中有 0 条记录，这也不起作用。 SQL 高手可以解决这个问题。感谢他们分享知识。

CREATE OR ALTER Trigger [dbo].[tr_Merge_Personal_Expense] on [dbo]. 
[Personal_Expense_Staging]
AFTER INSERT
AS

BEGIN

DECLARE @SummaryOfChanges TABLE(Change nvarchar(20));

         MERGE [dbo].[Personal_Expense] AS TARGET 
         USING (
         SELECT *,
                CHECKSUM(
                             ISNULL(CONVERT(nvarchar (3) ,[Client]),'0'),
                             ISNULL(CONVERT(nvarchar (50),[Text]),'0'),
                             ISNULL(CONVERT(nvarchar (10),[Cost_Center]),'0'),
                             ISNULL(CONVERT(nvarchar (2) ,[Posting_Period]),'0'),
                             ISNULL(CONVERT(nvarchar (10),[Profit]),'0') ,
                             ISNULL(CONVERT(nvarchar (2) ,[Document_Type]),'0'),
                             ISNULL(CONVERT(nvarchar (4) ,[Company_Code]),'0') ,
                             -- ISNULL(CONVERT(nvarchar (10),[Account]),'0'),
                             ISNULL(CONVERT(nvarchar (20),[Amount_In_Doc_Curr]),'0'),
                             ISNULL(CONVERT(nvarchar (5) ,[Document_Currency]),'0') ,
                             ISNULL(CONVERT(nvarchar (20),[Amount_In_local_Curr]),'0') ,
                             ISNULL(CONVERT(nvarchar (20),[Amount_In_Grp_Curr]),'0'),
                             ISNULL(CONVERT(nvarchar (25),[Group]),'0'),
                             [Posting_Date],
                             ISNULL(CONVERT(nvarchar (18), [Assignment]),'0'),
                             ISNULL(CONVERT(nvarchar (16), [Reference]),'0'),
                             ISNULL(CONVERT(nvarchar (20), [Reference_Key1]),'0') ,
                             --[Reference_Key2] [nvarchar](12) NOT NULL,
                             ISNULL(CONVERT(nvarchar (20), [Reference_Key3]),'0') ,
                             ISNULL(CONVERT(nvarchar (20), [Document_Number]),'0') ,
                             ISNULL(CONVERT(nvarchar (25), [Document_Header_Text]),'0') 
                 ) AS [HashChecksum]
         FROM
         [dbo].[Personal_Expense_Staging]
         ) AS SOURCE 
         ON (
                TARGET.[Reference_Key2] = SOURCE.[Reference_Key2] AND
                TARGET.[Account] = SOURCE.[Account] 
            )

         -----   Update 
         WHEN MATCHED AND ( TARGET.[HashChecksum] <> SOURCE.[HashChecksum] ) 
         THEN
         UPDATE SET  
                TARGET.[client] = SOURCE.[client],
                TARGET.[text] = SOURCE.[text],
                TARGET.[cost_center] = SOURCE.[cost_center],
                TARGET.[posting_period] = SOURCE.[posting_period],
                TARGET.[profit] = SOURCE.[profit],
                TARGET.[document_type]= SOURCE.[document_type],
                TARGET.[company_code] = SOURCE.[company_code],
                TARGET.[Account] = SOURCE.[Account],
                TARGET.[Amount_In_Doc_Curr] = SOURCE.[Amount_In_Doc_Curr],
                TARGET.[document_currency] = SOURCE.[document_currency],
                TARGET.[Amount_In_local_Curr] = SOURCE.[Amount_In_local_Curr],
                TARGET.[Amount_In_Grp_Curr] = SOURCE.[Amount_In_Grp_Curr],
                TARGET.[group] = SOURCE.[group],
                TARGET.[posting_date] = SOURCE.[posting_date],
                TARGET.[assignment] = SOURCE.[assignment],
                TARGET.[reference] = SOURCE.[reference],
                TARGET.[document_header_text] = SOURCE.[document_header_text],
                TARGET.[Last_updated_DateTime] = GETDATE(),
                TARGET.[HashChecksum] =  SOURCE.[HashChecksum]

         -- Insert 

         WHEN NOT MATCHED THEN
         INSERT ( 
                       [Client],
                       [text],
                       [cost_center],
                       [posting_period],
                       [profit],
                       [document_type],
                       [company_code],
                       [Account],
                       [Amount_In_Doc_Curr],
                       [document_currency],
                       [Amount_In_local_Curr],
                       [Amount_In_Grp_Curr],
                       [group],
                       [posting_date],
                       [assignment],
                       [reference],
                       [reference_key2],
                       [reference_key3],
                       [document_number],
                       [document_header_text],
                       [Last_updated_DateTime],
                       [HashChecksum]
         )
         VALUES (
                SOURCE.[client],
                SOURCE.[text],
                SOURCE.[cost_center],
                SOURCE.[posting_period],
                SOURCE.[profit],
                SOURCE.[document_type],
                SOURCE.[company_code],
                SOURCE.[Account],
                SOURCE.[Amount_In_Doc_Curr],
                SOURCE.[document_currency],
                SOURCE.[Amount_In_local_Curr],
                SOURCE.[Amount_In_Grp_Curr],
                SOURCE.[group],
                SOURCE.[posting_date],
                SOURCE.[assignment],
                SOURCE.[reference],
                SOURCE.[reference_key2],
                SOURCE.[reference_key3],
                SOURCE.[document_number],
                SOURCE.[document_header_text],
                GETDATE(),
                SOURCE.[HashChecksum]
         )

   OUTPUT $action INTO @SummaryOfChanges;

   DECLARE @RowsProcessed INT = 0;

   SELECT 
          @RowsProcessed = ISNULL([INSERT],0) + ISNULL([UPDATE],0) + ISNULL([DELETE],0)
   FROM (
         SELECT COUNT(*) ChangeCount, Change as ChangeType 
         FROM @SummaryOfChanges
         GROUP BY Change
   )Main
   PIVOT ( 
         MAX(ChangeCount)
         FOR ChangeType IN ([INSERT],[UPDATE],[DELETE])
   )Pvt;

   SELECT @RowsProcessed AS RowsProcessed;


CREATE OR ALTER TRIGGER [dbo].[tr_merge_personal_expense] 
ON personal_expense_staging 
AFTER INSERT AS

----- CASE 1: IF (ACCOUNT AND REF_KEY2) ARE MATCHED THEN UPDATE
IF EXISTS
(
  SELECT 
         *
  FROM   dbo.personal_expense p
         INNER JOIN inserted e
         ON p.[account] = e.[account] AND p.[reference_key2] = e.
         [reference_key2]
)
    BEGIN
        UPDATE target
          SET  
              target.[document_number] = source.[document_number],
              target.[client] = source.[client],
              target.[text] = source.[text],
              target.[cost_center] = source.[cost_center],
              target.[posting_period] = source.[posting_period],
              target.[profit] = source.[profit],
              target.[document_type] = source.[document_type],
              target.[company_code] = source.[company_code],
              target.[amount_in_doc_curr] = source.[amount_in_doc_curr],
              target.[document_currency] = source.[document_currency],
              target.[amount_in_local_curr] = source.[amount_in_local_curr],
              target.[amount_in_grp_curr] = source.[amount_in_grp_curr],
              target.[group] = source.[group],
              target.[posting_date] = source.[posting_date],
              target.[assignment] = source.[assignment],
              target.[reference] = source.[reference],
              target.[reference_key1] = source.[reference_key1],
              target.[reference_key3] = source.[reference_key3],
              target.[document_header_text] = source.[document_header_text],
              target.[last_updated_datetime] = GETDATE()
        FROM   personal_expense target
               INNER JOIN inserted source
               ON target.[account] = source.[account] 
               AND target.[reference_key2] = source.[reference_key2];
END;

        ------ CASE 2: IF (ACCOUNT AND REF_KEY2) ARE NOT MATCHED THEN INSERT
        IF NOT EXISTS
        (
          SELECT 
                 *
          FROM   dbo.personal_expense p
                 INNER JOIN inserted e
                 ON p.[account] = e.[account] AND p.[reference_key2] = e.
                 [reference_key2]
        )
            BEGIN
                INSERT INTO dbo.personal_expense
                (
                       [client],
                       [text],
                       [cost_center],
                       [posting_period],
                       [profit],
                       [document_type],
                       [company_code],
                       [account],
                       [amount_in_doc_curr],
                       [document_currency],
                       [amount_in_local_curr],
                       [amount_in_grp_curr],
                       [group],
                       [posting_date],
                       [assignment],
                       [reference],
                       [reference_key1],
                       [reference_key2],
                       [reference_key3],
                       [document_number],
                       [document_header_text],
                       [last_updated_datetime]
                )
                       SELECT 
                              source.[client],
                              source.[text],
                              source.[cost_center],
                              source.[posting_period],
                              source.[profit],
                              source.[document_type],
                              source.[company_code],
                              source.[account],
                              source.[amount_in_doc_curr],
                              source.[document_currency],
                              source.[amount_in_local_curr],
                              source.[amount_in_grp_curr],
                              source.[group],
                              source.[posting_date],
                              source.[assignment],
                              source.[reference],
                              source.[reference_key1],
                              source.[reference_key2],
                              source.[reference_key3],
                              source.[document_number],
                              source.[document_header_text],
                              GETDATE()
                       FROM   inserted source;
            END;

Answer 1

所以，你知道 of duplicates, merge statement producing an error。然后使用 DISTINCT:

简单地删除源子句中的重复项

SELECT DISTINCT *
FROM [dbo].[Personal_Expense_Staging]

在 MERGE SQL 查询中遇到问题

Facing an issue in MERGE SQL query

sql-server

insert-update

merge-statement