White spaces when updating varchar field using iif in firebird
I see strange result when executing this query
update sd_invodt set line_type=iif(is_promo=1, 'campaign', 'item')
The value in line_type field will be "item " . There are whitespaces in value. But when I execute this query
update sd_invodt set line_type='item'
I don't get white spaces.
Now I have to use trim as workaround
update sd_invodt set line_type=trim(iif(is_promo=1, 'campaign', 'item'))
I use latest firebird 2.5. Line_type is a varchar(15).
Is this bug in Firebird?
EDIT
I have tested using new database, and the problem persists.
The result type of the iif() depends on input and in case of string the result type seems to be char(x) where x is the length of the longest input string. Thus the "item" will be padded with 4 spaces to make it as long as the "campaign" is. I think this is by design but you may want to enter an ticket to the FB issuetracker.
So the iif() return "item " in case of first parameter being false and when you store spaces onto varchar field they are preserved.
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