On 2017-01-16 09:59, Thomas Kellerer wrote:
> Mark Rotteveel schrieb am 16.01.2017 um 09:37:
>> As far as I know the JDBC spec defers to the SQL standard
>> specification for this. Unfortunately I don't have a copy handy to
>> check how the SQL standard defines it.
>
>
> <boolean value expression> ::=
> <boolean term>
> | <boolean value expression> OR <boolean term>
>
> <boolean term> ::=
> <boolean factor>
> | <boolean term> AND <boolean factor>
>
> <boolean factor> ::=
> [ NOT ] <boolean test>
>
> <boolean test> ::=
> <boolean primary> [ IS [ NOT ] <truth value> ]
>
> <truth value> ::=
> TRUE
> | FALSE
> | UNKNOWN
>
> <boolean primary> ::=
> <predicate>
> | <boolean predicand>
>
> <boolean predicand> ::=
> <parenthesized boolean value expression>
> | <nonparenthesized value expression primary>
>
> <parenthesized boolean value expression> ::=
> <left paren> <boolean value expression> <right paren>
>
> so it boils down to
>
> <truth value> ::=
> TRUE
> | FALSE
> | UNKNOWN
>
> as far as I can tell.
IIRC, there is a section about conversion to boolean (maybe with CAST,
or maybe with the parameter specification), I'll try to find it when I
have access to a copy of the standard.
Mark