Nov
13

Tips & Tricks – Sybase T-SQL: <> does not match null values

MDBitz - Matthew Denton T-SQL, Tips & Tricks Add you comment

When writing SQL we may find that we need to write a WHERE clause that checks if a columns is not a certain value. To do this we have the <> operator that means does not equal. However you may be surprised that you are not getting all the results you expected, this is because <> does not match null values. To get all values that are not equal you need to check that a value is not equal or that it is null.

Examples SQL

SELECT * FROM CLIENT
WHERE SENSITIVE <> 'Y' or SENSITIVE IS null
, , ,