Understanding UNION and UNION ALL in SQL Server
A short look at the differences in UNION and UNION ALL in a SELECT query.
2025-04-07
4,249 reads
A short look at the differences in UNION and UNION ALL in a SELECT query.
2025-04-07
4,249 reads
Sometimes there is a need to combine data from multiple tables or views into one comprehensive dataset. This may be for like tables within the same database or maybe there is a need to combine like data across databases or even across servers. I have read about the UNION and UNION ALL commands, but how do these work and how do they differ?
2019-12-05
Paul White digs into row goals as he explains some interesting and inconsistent behavior with UNION ALL queries in SQL Server.
2017-06-13
5,896 reads
By Kevin3NF
Don’t Let Trouble Sneak Up on You Most SQL Servers run quietly. Until...
By Steve Jones
I had a conversation with a customer asking this question: how can I tell...
By Chris Yates
There was a time when the Chief Data Officer lived in the shadows of...
Comments posted to this topic are about the item Create an HTML Report on...
Hi I have a SP that occasionally get this error: Cannot resolve the collation...
Hi everyone I am getting an error when I create the index but I...
I have two calls to the GENERATE_SERIES TVF in this code:
SELECT TOP 10 gs.value FROM GENERATE_SERIES(1, 10) AS gs ORDER BY NEWID () OPTION (RECOMPILE); go DECLARE @a int = 10; SELECT TOP (@a) gs.value FROM GENERATE_SERIES(1, @a) AS gs ORDER BY NEWID () OPTION (RECOMPILE);In the actual query plans, what is the estimated number of rows for each batch in SQL Server 2022? See possible answers