Re: [HACKERS] Re: Informix and OUTER join syntax

> > SELECT *
> > FROM tab1, OUTER(tab2, OUTER tab3)
> > WHERE tab1.col1 = tab2.col1 AND
> > tab2.col1 = tab3.col1
> >It does the tab2, tab3 as an _outer_ join first, then _outer_ joins to
> >tab1. Can someone show me this in ANSI syntax?
> SELECT *
> FROM tab1 RIGHT JOIN (tab2 RIGHT JOIN tab3 on col1) on col1

Pretty sure this is correct (assuming that the Informix syntax is
showing a right-side outer join). istm that SQL92 is clearer, in the
sense that the WHERE clause in the Informix syntax specifies that
columns shall be equal, when in fact there is an implicit "or no
column matches" coming from the OUTER specification. SQL92 uses unique
syntax to specify this.

- Thomas

--
Thomas Lockhart lockhart(at)alumni(dot)caltech(dot)edu
South Pasadena, California