我有一个要求，将临时表 stgTbl 中的数据插入/更新到另一个表 T2。如果存在更新，则无论有多少重复项。同样，如果不存在直接插入T2。很简单。由于登台表 stgTb1 是每天安排的作业。有时我也会得到多个重复的行。所以由于重复，合并语句产生错误：
“MERGE 语句多次尝试更新或删除同一行。当目标行匹配多个源行时会发生这种情况”。
我尝试了校验和，但仍然得到，因为我可能在校验和中做错了。两个表中都没有主键（我删除了，否则我会收到主键约束错误）。基于列（帐户和 ref_key2）应该与插入/更新一起使用。我也尝试过 if else with exists 但不知何故，如果目标表 T2 中有 0 条记录，这也不起作用。SQL 大师可以解决这个问题。欣赏他们的知识分享。
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;