Solved

Oracle SQL IN Operator AND OR

Posted on 2008-06-18
5
1,169 Views
Last Modified: 2013-12-12
Hi,
I have the same list of text values which are being compared to two different fields using the IN operator. I get different results if i bracket the AND OR as per below. Which one should I be using?

SELECT * FROM TABLE
WHERE FIELDA IS NOT NULL
AND FIELDB IN (ETC,ETC)
OR FIELDC IN (ETC,ETC)

or

SELECT * FROM TABLE
WHERE FIELDA IS NOT NULL
AND
(FIELDB IN (ETC,ETC)
OR FIELDC IN (ETC,ETC))

Cheers,
Brett
0
Comment
Question by:brettanderson77
  • 3
  • 2
5 Comments
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 21812160
>I get different results if i bracket the AND OR as per below.
that is normal

>Which one should I be using?
depends on what result you want.

if you use AND, both fields must match, if you use OR, either field match will return the row.
0
 

Author Comment

by:brettanderson77
ID: 21812263
Hi,

Thanks for the response yet the question is not around AND/OR specifically, it is around using brackets.

Both options are using AND and OR in a similar manner yet one has the two OR options bracketed to seperate it from the first condition.

Op 1:
Where Condition 1
AND Condition 2
OR Condition 3

Op 2:
Where Condition 1
AND
 (Condition 2
OR Condition 3)

Hope you get my drift?

Cheers,
Brett
0
 
LVL 142

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 500 total points
ID: 21812461
I see.
indeed, using brackets when mixing AND and OR are important, as

Op 1:
Where Condition 1
AND Condition 2
OR Condition 3

will work like this:

Where (Condition 1
AND Condition 2)
OR Condition 3

which is indeed different as from Op2 code...

hence => rule: when having both AND and OR in a condition, put the ( ) as needed to ensure
1) the conditions are applied "correctly"
2) better readability

note: from technical term, they will be evaluated technically as they are written, it's just a what you expect might differ :)
0
 

Author Comment

by:brettanderson77
ID: 21812693
Great, thank you. So I think I was on the right track with using option 2 which will give me:

Condition 1 is true
AND
(Condition 2 OR 3 are true)

Let me know if i'm wrong!

Cheers,
Brett
0
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 21812900
you got it!
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Why doesn't the Oracle optimizer use my index? Querying too much data Most Oracle developers know that an index is useful when you can use it to restrict your result set to a small number of the total rows in a table. So, the obvious side…
Introduction A previously published article on Experts Exchange ("Joins in Oracle", http://www.experts-exchange.com/Database/Oracle/A_8249-Joins-in-Oracle.html) makes a statement about "Oracle proprietary" joins and mixes the join syntax with gen…
This video shows information on the Oracle Data Dictionary, starting with the Oracle documentation, explaining the different types of Data Dictionary views available by group and permissions as well as giving examples on how to retrieve data from th…
Video by: Steve
Using examples as well as descriptions, step through each of the common simple join types, explaining differences in syntax, differences in expected outputs and showing how the queries run along with the actual outputs based upon a simple set of dem…

867 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now