Solved

How can I use listagg with distinct.

Posted on 2016-08-31
4
388 Views
Last Modified: 2016-09-01
Dear Experts,

My requirement is to get distinct values after I use listagg.
But distinct is not allowed inside listagg,

Please help !!
0
Comment
Question by:sakthikumar
[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
  • 2
4 Comments
 
LVL 74

Expert Comment

by:sdstuber
ID: 41778145
simply wrap your source data in an inline view and make that distinct, then select listagg from that

for example...

select listagg(owner,',') within group(order by owner) from
     (select distinct owner from all_objects)
0
 
LVL 5

Expert Comment

by:Abhimanyu Suri
ID: 41778154
Can you please quote an example

If it is one row o/p combined with listagg, below example may help

SELECT LISTAGG (usr, ',') WITHIN GROUP (ORDER BY usr)
  FROM (SELECT DISTINCT username usr FROM USERS)
0
 

Author Comment

by:sakthikumar
ID: 41778221
the column already has comma separated values, so distinct is not working.

data is like below

category  email
a                email1,email2,email3
b               email2,email3,email6

when I do a group I should get only distinct email IDs
0
 
LVL 74

Accepted Solution

by:
sdstuber earned 500 total points
ID: 41778241
then you need to split your data first, then combine it afterward.


SELECT LISTAGG(email, ',') WITHIN GROUP (ORDER BY email)
  FROM (SELECT DISTINCT REGEXP_SUBSTR(
                            email,
                            '[^,]+',
                            1,
                            COLUMN_VALUE
                        )
                            email
          FROM yourdata,
               TABLE(
                       SELECT COLLECT(LEVEL)
                         FROM DUAL
                   CONNECT BY LEVEL <= REGEXP_COUNT(email, '[^,]+')
               ))

Open in new window

1

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

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 shows setup options and the basic steps and syntax for duplicating (cloning) a database from one instance to another. Examples are given for duplicating to the same machine and to different machines
This video shows how to recover a database from a user managed backup

738 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