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IsNull() function

hi, can anybody tell me in simple words what is IsNull() and why and where is it used?

15 Replies
Partner - Specialist III
Partner - Specialist III


Please read this blog post by HIC for better understanding of NULL


IsNull(expr) returns -1 (true) if expr returns NULL, otherwise 0 (false).

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Creator III
Creator III

Hi Gysbert

How can we use following in Qlik?

,ISNULL(I.instrumentcusip,ISNULL(I.instrumentsedol,ISNULL(I.instrumentisin,I.instrumentticker))) AS [SECURITY ID]



You can use it as text to fill some space. Put '//' in front of it and it can be used as a comment.

Isnull takes only one argument. So it you try to use it with two arguments your script will throw an error.

If you have a question then creating a new discussion for it is a better idea than digging up a discussion that's been dead and buried for three years.

talk is cheap, supply exceeds demand