?
Solved

finding common records from two tables

Posted on 2013-01-07
8
Medium Priority
?
283 Views
Last Modified: 2013-02-05
I have two tables with same columns  i have key based upon that key i want to see  if i have any dups or common records for that two tables

how can i do that.

Thanks
0
Comment
Question by:sam2929
[X]
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
  • 5
  • 2
8 Comments
 
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 38752661
Use intersect?

select key_col1, key_col2 from table1
intersect
select key_col1, key_col2 from table2
/

You could join them as well but I figure intersect will be faster.
0
 
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 38752663
forgot the join:

select t1.keycol1, t1.keycol2 from tab1 t1, tab2 t2
where t1.keycol1=t2.keycol1 and t1.keycol2=t2.keycol2;
0
 
LVL 14

Expert Comment

by:ajexpert
ID: 38753060
You can also try out EXISTS clause.

assuming you want data only from table1 that EXISTS in table2

select t1.* from tab1 t1
WHERE EXISTS
(select 1 from tab2 t2
where t1.col1=t2.col1
and t1.col2=t2.col2)
0
Visualize your virtual and backup environments

Create well-organized and polished visualizations of your virtual and backup environments when planning VMware vSphere, Microsoft Hyper-V or Veeam deployments. It helps you to gain better visibility and valuable business insights.

 

Author Comment

by:sam2929
ID: 38753126
Now i want to delete the dups how can i do that
0
 
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 38753138
Something like:
Delete from table1 where rowid in
(
Select t1.rowid
From ...whatever select you wanted to use
)

If you want to delete from table2, just switch the names.
0
 
LVL 77

Expert Comment

by:slightwv (䄆 Netminder)
ID: 38753141
Oops.

That deletes all rows.  If that isn't what you want, just let us know.
0
 

Author Comment

by:sam2929
ID: 38753305
No i don't want to delete all rows

table a looks like

doc_num    yr           line
123            2010         1
234            2010         1

table b looks like
doc_num    yr           line
123            2010         1
345           2010         1

i want final result as
doc_num    yr           line
234            2010         1

table b looks like
doc_num    yr           line
123            2010         1
345           2010         1
0
 
LVL 77

Accepted Solution

by:
slightwv (䄆 Netminder) earned 2000 total points
ID: 38753339
I didn't mean ALL rows.  I just meant all 'matching' rows. That is what you showed in the results.

When trying things like this, set up a simple test case to see what happens.

Here is a complete test using your sample data.  If you do not get the expected results, please add to it and show where it fails.

drop table taba purge;
create table taba(doc_num number, yr number, line number);

drop table tabb purge;
create table tabb(doc_num number, yr number, line number);

insert into taba values(123,2010,1);
insert into taba values(234,2010,1);

insert into tabb values(123,2010,1);
insert into tabb values(345,2010,1);
commit;

delete from taba
where (doc_num,yr,line) in (select doc_num,yr,line from tabb);
commit;

select * from taba;
select * from tabb;

Open in new window

0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

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

Configuring and using Oracle Database Gateway for ODBC Introduction First, a brief summary of what a Database Gateway is.  A Gateway is a set of driver agents and configurations that allow an Oracle database to communicate with other platforms…
Checking the Alert Log in AWS RDS Oracle can be a pain through their user interface.  I made a script to download the Alert Log, look for errors, and email me the trace files.  In this article I'll describe what I did and share my script.
This video explains at a high level about the four available data types in Oracle and how dates can be manipulated by the user to get data into and out of the database.
This video shows how to recover a database from a user managed backup
Suggested Courses

741 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