Re:TQuery and SQL's OUTER JOINS
In article <201095.2148393761...@frontier.canrem.com>
msvari...@frontier.canrem.com "Marcel Svaricek" writes:
Quote
> I have been trying to use an outer join SQL command in a TQuery component to
> join 3 tables.
> I am not very familiar with SQL syntax and I am not sure if it can be done.
> The only resource I have on SQL is the BORLAND's Local Interbase Server user
> guide
> where it says that joins can be done on two or more tables but it doesn't say
> if this applies to outer joins.
> Example (this doesn't work):
> SELECT a.*, b.*, c.*
> FROM table1 a OUTER JOIN table2 b OUTER JOIN table3 c
> ON a.no = b.no
> AND b.no = c.no
> AND b.no2 = c.no2
> If anyone knows how this can be done please get back to me.
Without actually trying it I suspect the syntax should be
SELECT * FROM table1, table2, table3,
table1 LEFT OUTER JOIN table2 ON table1.no = table2.no,
table1 RIGHT OUTER JOIN table3 ON table1.no = table3.no
The commas at the end of each line are required (I think).
The SQL reference on using Local SQL (as opposed to ISQL) is in Appendix C
of the Database Application Developer's Guide.
--
Richard Linsley Hood | Poole, Dorset UK | email: richar...@dakal.demon.co.uk
"Programming is mirroring the world, inside a computer" Larry O'Brien 1991