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sqlsql-server

Trimming empty string or spaces in SQL

What happens when you try and trim an empty string or a bunch of spaces in SQL Server? Does it become null or ''?

Solution

  • Here's an easy way to test string manipulations, manually throw some strings together and find out:

    ;with cte as (SELECT '   0   ' AS col 
              UNION SELECT '      ' AS col 
              )
SELECT LTRIM(RTRIM(col)) as col
FROM cte

    Which returns a zero and a blank string. To get a NULL you'd have to use NULLIF()