Re: Cast '' (blank) to null date

"Mattis Jiderhamn" <mattias@expertsystem.se> writes:
> I'm trying to create a trigger so that, if I try to insert blank, that is
> '', into a date field it will be converted to null so that I don't get
>   ERROR:  Bad date external representation ''

I don't think it's possible to do that with a trigger.  By the time the
trigger is called, the proposed row has already been formed, so any
input data conversion errors that might occur will already have
occurred.

You'll have to code the substitution on the application side, or perhaps
in the SQL query with a CASE expression.
        regards, tom lane