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How to avoid duplicates in a MERGE statement?
EDIT In my original post I only included two fields in the example tables which gave way to SO friends to give a DISTINCT solution to avoid duplicates in the MERGE statement. I should have mentioned that in my real-world problem the tables have 15 fields and of those 15, two of the fields are a CLUSTERED PRIMARY KEY.
How to avoid inserting duplicate records when using a T-SQL?
Only inserting the highest value of col4: This time I used a group by to prevent duplicate rows. MERGE INTO dbo.tbl1 AS tbl USING (SELECT col2,col3, max (col4) col4 FROM #tmp group by col2,col3) AS src ON (tbl.col2 = src.col2 AND tbl.col3 = src.col3) WHEN NOT MATCHED THEN INSERT (col2,col3,col4) VALUES (src.col2,src.col3,src.col4);
Can a MERGE statement update the same table multiple times?
A MERGE statement cannot UPDATE/DELETE the same row of the target table multiple times. Refine the ON clause to ensure a target row matches at most one source row, or use the GROUP BY clause to group the source rows. The wording of this error message seems to imply my desired validation should be occurring already.
When do MERGE statements fail in SQL Server?
The error message that only comes on the second and subsequent executions: Msg 8672, Level 16, State 1, Line 4 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. A MERGE statement cannot UPDATE/DELETE the same row of the target table multiple times.
How can I remove ” duplicate ” rows from a view?
I say “duplicate” because the second row has a different value. However, if I change the LEFT OUTER to an INNER JOIN, I lose all the rows for the clients who have these “duplicate” rows. What am I doing wrong? How can I remove these “duplicate” rows from my view? This question is not applicable in this instance: How can I remove duplicate rows?
What happens when I merge two bi tables?
Both tables have unique records on each row. When I join the tables, BI creates duplicate rows on some records for no apparent reason. The duplicates are identical in every way.
What causes Power BI to create duplicate rows?
When I join the tables, BI creates duplicate rows on some records for no apparent reason. The duplicates are identical in every way. Can anybody explain this? Is this a bug? Solved! Go to Solution. 02-16-2017 01:42 AM The problem lay with the Data. The LEFT JOIN functionality of PowerBI works perfectly. 09-25-2020 08:37 AM I had same problem.