Re: Updatable views/with check option parsing

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> I had a quick look - I don't think there is an easy answer with the
> current proposed grammar. If we want to prevent shift/reduce conflicts I
> suspect we'd need to use a different keyword than WITH, although I can't
> think of one that couldn't be a trailing clause on a select statment,
> which is the cause of the trouble. Another possibility would be to move
> the optional WITH clause so that it would come before the AS clause.

Unfortunately the SQL99 spec is perfectly clear about what it wants:

<view definition> ::=
CREATE [ RECURSIVE ] VIEW <table name>
<view specification>
AS <query expression>
[ WITH [ <levels clause> ] CHECK OPTION ]

<levels clause> ::=
CASCADED
| LOCAL

I haven't had time to play with this yet, but I suspect the answer will
have to be that we reinstate the token-merging UNION JOIN kluge that I
just took out :-(. Or we could look into recognizing the whole thing as
one token in scan.l, but I suspect that doesn't work unless we give up
the no-backtrack property of the lexer, which would be more of a speed
hit than the intermediate function was. Anyway it should certainly be
soluble with token merging, if we can't find a pure grammar solution.

regards, tom lane