Oracle 11g bug ?!

Question

We are trying to execute a simple query of the form
select * from sometable where upper(attr1) like 'WB%' or upper(attr2) like 'WB%' or upper(attr3) like 'WB%'
The data does exist in the table but the query does not return values.
Sometimes the count(*) on that table returns the correct number but the actual select statement does not return data.
We have added a dummy where clause
select * from sometable where upper(attr1) like 'WB%' or upper(attr2) like 'WB%' or upper(attr3) like 'WB%' or lower(attr2) like 'WB%' and the data does show up.
We are on Oracle 11g 11.2.0.2 and have migrated recently from 10g. And this issue has started appearing after the migration.
Any thoughts on what could be causing this issue ?
Thanks
Surya
Edited by: Surya on 09-Mar-2011 06:11

Answer 1

user11180582 wrote:
We have added a dummy where clause
select * from sometable where upper(attr1) like 'WB%' or upper(attr2) like 'WB%' or upper(attr3) like 'WB%' or lower(attr2) like 'WB%' and the data does show up. Hm. difficult but I doubt that you have a bug. I guess you have either some strange values or there is something in the full statement that is missing in your example.
For example please be aware that the AND operator has a higher priority then the OR operator (is this way since oracle 7 at least).
So if your real statement would include an and condition, this could produce unwanted outcome.
select * from sometable
where upper(attr1) like 'WB%'
     or upper(attr2) like 'WB%'
     or upper(attr3) like 'WB%'
     and lower(attr5) = 'XY' This is identical to:
select * from sometable
where upper(attr1) like 'WB%'
     or upper(attr2) like 'WB%'
     or (upper(attr3) like 'WB%' and lower(attr5) = 'XY' )But usually you want
select * from sometable
where (upper(attr1) like 'WB%' or upper(attr2) like 'WB%' or upper(attr3) like 'WB%')
        and lower(attr5) = 'XY' Some additon. Your condition could also be written like this. Maybe this helps to find the real cause of the error.
select * from sometable
where 'WB' in (substr(upper(attr1),1,2)
                   ,substr(upper(attr2),1,2)
                   ,substr(upper(attr3),1,2)
                   )I find this often to be better readable then a long LIKE + OR expression.