Hi,
we need to process user-defined integrity conditions, which are stored as
strings at application level, e. g. "person.age - 2 > 18". We would like to
substitute the variable names within these expressions by their values at
trigger time. So we have expressions containing constants only, e. g. "29 - 2
> 18". We are glad to have found out that we can evaluate such expressions
simply by calling them with SELECT, e. g. "SELECT 29 - 2 > 18" returns true.
We think that it would be very nice to benefit from the pg database system
parser. But can we rely on this functionality in the future? Is this standard
SQL?
Thank you,
Markus