Solved

Select distinct column

Posted on 2006-11-26
8
484 Views
Last Modified: 2007-08-27
Hi,
I have a database with where a value in a column may appear many times. It would be easy to select the distinct values from this column on its own but I need to also return other columns. Therefore the distinct clause will apply to all the columns being returned (so distinct is where column a, b, c and d are distinct). I suppose then my question is simply how do I return distinct values from column a and also return column b and c (therefore just taking say the distinct values from column a and ignoring the fact that value may appear again in the column).
Hope you can understand me.
thanks in advance
0
Comment
Question by:manukaucouncil
  • 4
  • 2
  • 2
8 Comments
 
LVL 3

Expert Comment

by:dave_gr
ID: 18015474
select distinct colA, colB, colC, colD from sourceTable

or

select colA, colB, colC, colD
from sourceTable
group by colA, colB, colC, colD

Not sure if that answers your question mind, as I'm not really sure what you are asking.

David
0
 

Author Comment

by:manukaucouncil
ID: 18015527
when you use "select distinct colA, colB, colC, colD from sourceTable" does that mean that colA, colB, colC and colD need to be distinct together or is it just distinct colA? Say for example I want to just return distinct colB values... how would I do this as select colA, distinct colB....... does not work.
0
 
LVL 3

Expert Comment

by:dave_gr
ID: 18015703
If you just want distinct colB values then you can do

select distinct colB from sourceTable

for distinct colA then

select distinct colA from sourceTable

for every distinct combination of colA and colB you

select distinct colA, colB from sourceTable


What are your columns?  What are you trying to achieve?

0
 

Author Comment

by:manukaucouncil
ID: 18015922
This is my script:
select amount_id, adjust_id, amttyp_id, description, order_no, essbase_account_id, essbase_entity_id, ltrim(STR(adjust_id)) + 'a' +  ltrim(STR(order_no)) AS adjust_order, amount_id from atm_amount where essbase_account_id in (select dimension_1_node_key from dss_dimension_1 where node_desc = 'PS3001') and adjust_id in (select distinct adjust_id from atm_adjustment where adjtyp_id in (1,2) and status_id <7) order by adjust_id,order_no

Bascically I just want to return the distinct adjust_id's in the outer select statement but with the other information still attached to it.
0
Optimizing Cloud Backup for Low Bandwidth

With cloud storage prices going down a growing number of SMBs start to use it for backup storage. Unfortunately, business data volume rarely fits the average Internet speed. This article provides an overview of main Internet speed challenges and reveals backup best practices.

 
LVL 39

Expert Comment

by:appari
ID: 18016031
do you mean you want
adjust_id in (select distinct adjust_id from atm_adjustment where adjtyp_id in (1,2) and status_id <7) order by adjust_id,order_no
to
adjust_id in (select distinct adjust_id, other1,other2 from atm_adjustment where adjtyp_id in (1,2) and status_id <7) order by adjust_id,order_no


if you add other information in the outer select you cannot use it with "in" condition.

why do you need other information in that outer sql? can you explain what you are trying to do?
0
 

Author Comment

by:manukaucouncil
ID: 18016244
Say for example I have this data:

ClassName         ClassDescription                StudentName              Mark
SQL Server         All about SQL                      Jeremy                        A
VB                      All about VB                        Jeremy                        A+
SQL Server        All about SQL 2                       Bob                             B

Now I want to do something like this: "select distinct classname, classdescription, studentname, mark from table"
The problem with this script is that it will recognise rows 1 and 3 as distinct because they have a different description.
So I really only want the distinct clause to apply to classname so the results return as follows:

ClassName         ClassDescription                StudentName              Mark
SQL Server         All about SQL                      Jeremy                        A
VB                      All about VB                        Jeremy                        A+

So it just ignores the second occurance of SQL Server in classname.
I hope that makes it a bit clearer.
0
 
LVL 39

Accepted Solution

by:
appari earned 250 total points
ID: 18016377
in case of class name repeatition which record you want to show?
but studentname is different in your sample data. even if studentname is different you want to show only one record?
in that case you have to use group by classname and use some aggregate function on the remaining columns.
decide on what to use max or min .

SQL will be something like this

select ClassName, min(ClassDescription) ClassDescription, min(StudentName) StudentName, max(Mark) Mark
from yourtable
0
 

Author Comment

by:manukaucouncil
ID: 18016380
Ahhh that certainly makes sense. Thanks
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

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

This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
For both online and offline retail, the cross-channel business is the most recent pattern in the B2C trade space.
Familiarize people with the process of utilizing SQL Server functions from within Microsoft Access. Microsoft Access is a very powerful client/server development tool. One of the SQL Server objects that you can interact with from within Microsoft Ac…
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.

912 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

20 Experts available now in Live!

Get 1:1 Help Now