Comparing Nulls Inside a Conditional Split

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Comparing Nulls Inside a Conditional Split

dndaughtery

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Points: 11290
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June 21, 2010 at 9:11 am

#145366

I have a conditional split where I'm comparing two columns where it is certain that they can have null values. I'm writing the expression as follows:
var_a == var_b
but I'm noticing that this is never evaluating to true when the values are null. How can I get around this?
June 22, 2010 at 6:46 am

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dndaughtery SSChampion Points: 11290 More actions · Answer 1

I never found an easy fix for this but managed to find a work around. I changed my datasource task to use a "Select" statement and added the ISNull(Fildname,'') in the select statment

vineet_ SSC-Addicted Points: 475 More actions · Answer 2

TRY THIS:

ISNULL([var_a] == [var_b]) ? (ISNULL([var_a]) && ISNULL([var_b])) : [var_a] == [var_b]

LET ME KNOW IF IT WORKS

THNX

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Why not ?

Koen Verbeeck SSC Guru Points: 259135 More actions · Answer 3

You just can't compare two values if there are possible null values. You can compare null with "unknown", so your expression will fail sometimes.

So, either clean-up your input with isnull, as you did, or write an expression in the conditional split that checks for null values, as vineet1234 proposed.

@vineet1234: your caps-lock is broken. You should try out another keyboard.

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