Darryl Dixon <darryl(dot)dixon(at)gmail(dot)com> writes:
> The bug is that:
> 1) The concatenation is not producing NULL, but rather Text, and yet the
> comparison fails regardless, and
> 2) The explicit CAST of NULL -> Text fails to remedy this.
I wonder what you think NULL means. You certainly don't appear to
understand its semantics at all. Every SQL data type allows NULL
as a value, so "casting NULL to text" doesn't change the value,
only what type the parser deems it to have.
> Further examples below:
Every one of these looks as-expected to me.
regards, tom lane