🚀 go-pugleaf

On Sat, 23 May 1998 16:40:03 GMT, fpolan@pcassist.on.ca (Frank Polan)
wrote:

>I've just started working my way thru " teach yourself SQL in 14 days"
>- SAMS Publishing 1995. I've come across 2 operators - INTERSECT and
>MINUS that don't seem to be in VDB7. They dont show up in another SQL
>book either
>
>Is VDB7 SQL incomplete or is the book out of date? Can anyone
>recommend a better one?

I cannot find a MINUS join operator in any of my SQL-92 specification
references. The INTERSECT join operator is part of the SQL-92
specification.

Local SQL (what the BDE uses for dBASE and Paradox tables) is a subset of
the SQL-92 specification. That is, it uses most language elements of
SQL-92, but not all. The INTERSECT join operator is an example of this, not
being included in the local SQL subset.

That is not to say that the INTERSECT join operator cannot be used in SQL
issued from a dBASE application. It just cannot be used with local tables.
If you have another table type, one that supports INTERSECT, you should be
able to use it in pass-through SQL.

The MINUS join operator represents an implementation-specific extension to
SQL-92. That is, MINUS represents additional functionality beyond that
defined in the SQL-92 specification and only a limited number of database
systems actually incorporate it.

SQL-92 language elements supported by local SQL are described in the local
SQL on-line help file, LOCALSQL.HLP, found in the BDE directory. The
current help does not list SQL-92 language elements that are *not*
supported in local SQL, future editions of this help file will.

**************************************************************************
Steve Koterski
INPRISE Corporation, Technical Publications
http://www.inprise.com/delphi