Query to find out records with duplicate of two columns combination

Posted on 2014-03-07
Last Modified: 2014-03-08
Query to find out records with duplicate of two columns combination

I have two tables that have the same structure but different data. Table names are a and b and column names to be used are c1, c2 (there are many other columns for table a or b)

select c1, c2 from a
c1 c2
2  UK
3  USA
5  Japan

select c1, c2 from b:
c1  c2
2   UK
3   USA
5   France

After the query, result should be (retrieve c1, c2 info from table a)
c1 c2
2   UK
3   USA

Again, note: I need to compare combined fields of c1 + c2

Thanks for any samples
Question by:heyday2004
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 35

Assisted Solution

by:Dan Craciun
Dan Craciun earned 250 total points
ID: 39914320
SELECT c1, c2, FROM a INNER JOIN b ON a.c1=b.c1

Open in new window


Assisted Solution

NARANTHIRAN earned 125 total points
ID: 39914321
select distinct TableA.*
  from TableA
       join TableB
         on TableA.A = TableB.A
        and TableA.B = TableB.B
LVL 57

Accepted Solution

Julian Hansen earned 125 total points
ID: 39914390
A Cross Join also works

SELECT * FROM tableA, tableB
WHERE tableA.c1 = tableB.c1 AND tableA.c2 = tableB.c2

Open in new window

When joining on more than 1 field I prefer to use a cross join than an inner join - it doesn't make much of a difference - just a preference.
LVL 35

Assisted Solution

by:Dan Craciun
Dan Craciun earned 250 total points
ID: 39914397
Sorry, it should of been:
SELECT a.c1, a.c2, 
        ON a.c1=b.c1 AND a.c2 = b.c2

Open in new window


Author Closing Comment

ID: 39915174

Featured Post

Will your db performance match your db growth?

In Percona’s white paper “Performance at Scale: Keeping Your Database on Its Toes,” we take a high-level approach to what you need to think about when planning for database scalability.

Question has a verified solution.

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

I'm trying, I really am. But I've seen so many wrong approaches involving date(time) boundaries I despair about my inability to explain it. I've seen quite a few recently that define a non-leap year as 364 days, or 366 days and the list goes on. …
This article shows the steps required to install WordPress on Azure. Web Apps, Mobile Apps, API Apps, or Functions, in Azure all these run in an App Service plan. WordPress is no exception and requires an App Service Plan and Database to install
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : All lightning effects with instructions : http://www.mediaf…

717 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