Re: Do all the legs of an "OR" with null comparisons get executed?

If I do an explain plan of the statement below I can see that the
"and" clauses that have MMDDOB=NULL do not get executed


select * from v_search where
UPP_FIRST='JOHN' and UPP_LAST='SMITH' and MMDDOB=NULL and AA=1 or
UPP_FIRST='JOHN' and UPP_LAST='SMITH' and BB=2 or
UPP_FIRST='JOHN' and UPP_LAST='SMITH' and CC='CA' or
UPP_FIRST='JOHN' and MMDDOB=NULL and AA=1 and BB=2 or
UPP_FIRST='JOHN' and MMDDOB=NULL and AA=1 and CC='CA' or
UPP_FIRST='JOHN' and BB=2 and CC='CA' or
UPP_LAST='SMITH' and MMDDOB=NULL and AA=1 and BB=2 or
UPP_LAST='SMITH' and MMDDOB=NULL and AA=1 and CC='CA' or
UPP_LAST='SMITH' and BB=2 and CC='CA' or
MMDDOB=NULL and AA=1 and BB=2 and CC='CA'


My problem is how to know if it does the same thing when I parametize
the query as


select * from v_search where
UPP_FIRST=:UPP_FIRST and UPP_LAST=:UPP_LAST and MMDDOB=:MMDD and
AA=:AA or
UPP_FIRST=:UPP_FIRST and UPP_LAST=:UPP_LAST and BB=:BB or
UPP_FIRST=:UPP_FIRST and UPP_LAST=:UPP_LAST and CC=:CC or
UPP_FIRST=:UPP_FIRST and MMDDOB=:MMDD and AA=:AA and BB=:BB or
UPP_FIRST=:UPP_FIRST and MMDDOB=:MMDD and AA=:AA and CC=:CC or
UPP_FIRST=:UPP_FIRST and BB=:BB and CC=:CC or
UPP_LAST=:UPP_LAST and MMDDOB=:MMDD and AA=:AA and BB=:BB or
UPP_LAST=:UPP_LAST and MMDDOB=:MMDD and AA=:AA and CC=:CC or
UPP_LAST=:UPP_LAST and BB=:BB and CC=:CC or
MMDDOB=:MMDD and AA=:AA and BB=:BB and CC=:CC


On Mar 28, 2:15 pm, Frank van Bortel <frank.van.bor...@xxxxxxxxx>
wrote:
Arthernan wrote:
That is an alternative. I do think the logic is correct thought. Take
the first comparison for example:

UPP_FIRST='JOHN' and UPP_LAST='SMITH' and MMDDOB=NULL and AA=1

MMDDOB=NULL should be "MMDDOB is NULL"

And no, Oracle is smart enough to know boolean algebra; if
a part of the boolean equation yields true (or false), the
rest is no executed - it would not change the outcome.

Now, you figure out when to OR or AND, and when TRUE or
FALSE :)
--

Regards,
Frank van Bortel

Top-posting in UseNet newsgroups is one way to shut me up

But if I did "MMDDOB is NULL" instead of MMDDOB=NULL. I would get
records back when I don't want them.

The final query will be parametized like this "MMDDOB=:MMDDOB". So I
want to know if :MMDDOB happens to be NULL, will oracle be smart
enougth to realize that whole "and clause" can go away. For example if
I did MMDDOB=1231, whenever MMDDOB was NULL the row would be filtered
out. Just look at my original SQL above and you will see what I mean.


Arturo Hernandez
.