[SQL] Is it This Join Condition Do-Able?

[Lane Van Ingen]

Given three tables: a, b, c ; each consist of a 'keyfld' and a field called
'foo':
     tbl a       tbl b         tbl c
   ---------   ---------     ---------
   a.keyfld    b.keyfld       c.keyfld
   a.foo1      b.foo2         c.foo3

I want to always return all of tbl a; and I want to return b.foo2 and c.foo3
if
they can be joined to based on keyfld.a; I know that it will involve a LEFT
OUTER
JOIN on table a, but have not seen any examples of joins like this on 3 or
more
tables.

select a.keyfld, a.foo1, b.foo2, c.foo3
from a, b, c
where a.keyfld = <some value>
and   a.keyfld = b.keyfld
and   a.keyfld = c.keyfld;

Results could look like this:
  a.keyfld  a.foo1   b.foo2  c.foo3
    xxxx     xxxx     xxxx    (null)
    xxxx     xxxx    (null)    xxxx
    xxxx     xxxx    (null)   (null)
    xxxx     xxxx     xxxx     xxxx



---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match