In SQL Server, an empty string and a NULL value are not the same.
As far as I know, NULLs and empty strings are equal in Oracle. But in SQL Server they are not.
To distinguish NULLs and empty strings or to find padding spaces I use
select '«' + @txt + '»'
The difference is visible at the first look. You can use some other type of quotes or brackets if you like.
Sorry to oraclists, I am used to MS SQL Server.
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