?
Solved

SQL concatinate

Posted on 2011-03-24
9
Medium Priority
?
410 Views
Last Modified: 2012-05-11
Hi,
I am trying to create a query that concatenates the columns into a single column delimited with a pipe.  It works, but if one of the columns are null, the answer is null.  How do I make it so my query will treat null as an empty string?

I will have the same issue with date and integer.

SELECT     EmpNo, AssociationName, MemberSince, Position, AssociationName + '|' + CONVERT(varchar, MemberSince) + '|' + Position AS ProfessionalAffiliationsFull
FROM         dbo.EmpAssociations AS e
0
Comment
Question by:jackjohnson44
  • 5
  • 3
9 Comments
 
LVL 40

Accepted Solution

by:
Richard Quadling earned 1000 total points
ID: 35210871
Rather than using ...

SELECT     EmpNo, AssociationName, MemberSince, Position, AssociationName + '|' + CONVERT(varchar, MemberSince) + '|' + Position AS ProfessionalAffiliationsFull
FROM         dbo.EmpAssociations AS e

Open in new window


use ...

SELECT     EmpNo, AssociationName, MemberSince, Position, ISNULL(AssociationName, '') + '|' + ISNULL(CONVERT(varchar, MemberSince), '') + '|' + ISNULL(Position, '') AS ProfessionalAffiliationsFull
FROM         dbo.EmpAssociations AS e

Open in new window


You can read about the ISNULL function here.

Regards,

Richard.
0
 
LVL 32

Expert Comment

by:Ephraim Wangoya
ID: 35210908
Try this way
SELECT EmpNo, AssociationName, MemberSince, Position, 
       ISNULL(AssociationName + '|' , '')+ ISNULL(CONVERT(varchar, MemberSince) + '|', '') + ISNULL(Position, '') AS ProfessionalAffiliationsFull
FROM dbo.EmpAssociations AS e

Open in new window

0
 
LVL 40

Expert Comment

by:Richard Quadling
ID: 35211021
@ewangoya

It's a pain when you post a duplicate answer isn't it? <grin>
0
What Kind of Coding Program is Right for You?

There are many ways to learn to code these days. From coding bootcamps like Flatiron School to online courses to totally free beginner resources. The best way to learn to code depends on many factors, but the most important one is you. See what course is best for you.

 
LVL 32

Expert Comment

by:Ephraim Wangoya
ID: 35211039

@RQuadling

Please look carefully again. You will see a big difference
You query will put pipes even when the column value returns null
        XXX||YYY  or IXX|YY or IIXXX

Mine will not
0
 
LVL 32

Assisted Solution

by:Ephraim Wangoya
Ephraim Wangoya earned 1000 total points
ID: 35211068

@RQuadling

Basically this is what you are doing
ISNULL(AssociationName, '') + '|'
Even if the column is null, you are still returning '|'

Mine on the other hand is
ISNULL(AssociationName + '|' , '')

So if the column is null, I dont put in a | and its much cleaner result
0
 
LVL 40

Expert Comment

by:Richard Quadling
ID: 35211081
No. Please read the question ...

How do I make it so my query will treat null as an empty string?

So NULL => ''



0
 
LVL 40

Expert Comment

by:Richard Quadling
ID: 35211090
If the output is for a pipe delimited file (like a CSV file), then having a column or three missing is pretty much going to screw up the app/process that uses the file.
0
 

Author Comment

by:jackjohnson44
ID: 35211113
RQuadling, thanks that is what I was looking for.

How do I do the same for dates and integers?
0
 
LVL 40

Expert Comment

by:Richard Quadling
ID: 35212381
cast(isnull(a_numeric_column, 0) as varchar)

cast(isnull(a_date_column, '') as varchar)



0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

This shares a stored procedure to retrieve permissions for a given user on the current database or across all databases on a server.
Microsoft provides a rich set of technologies for High Availability and Disaster Recovery solutions.
Via a live example, show how to extract insert data into a SQL Server database table using the Import/Export option and Bulk Insert.
Via a live example, show how to shrink a transaction log file down to a reasonable size.

585 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