Re: Why the "UPDATE tab SET tab.col" is invalid?

"postgres_sure"<postgres_sure(at)163(dot)com> writes:
> I found "Do not include the table's name in the specification of a target column
> for example, UPDATE tab SET tab.col = 1 is invalid." in the documentation.

> Some people usually like to update table by alias. They want to add this feature.

Sorry, but we aren't ever going to accept such a patch, because it would
introduce an unavoidable ambiguity: is "SET a.b = " meant to be an
assignment to column b of table a, or is it meant to be an assignment to
sub-field b of composite column a?

Yeah, we could invent some resolution rules to deal with that, but
better to just not add the nonstandard syntax (and it IS nonstandard,
SQL:2011 has nothing about it) in the first place.

regards, tom lane