Concatenate SQL Server Columns into a String with CONCAT()

By:   |   Updated: 2021-07-21   |   Comments (17)   |   Related: 1 | 2 | 3 | 4 | 5 | 6 | > Functions System


I need to produce mailing labels from my Microsoft SQL Server database so I am using the + sign to concatenate the first, middle, and last names together. The issue I see is I get NULL for a lot of rows. This makes me unable to produce the full names. What are some options to address this problem? Check out this tutorial to learn more about concatenating data in SQL Server with T-SQL string concatenation.


Prior to SQL Server 2012 concatenation was accomplished by using the plus (+) sign to concatenate fields together of various data types (varchar, char, int, numeric, etc.). The limitation of this method is if any of the fields you are concatenating are NULL, the final string value is NULL. In SQL Server 2012 and later there is the CONCAT() function that replaces NULL with an empty string. Take a look at this tip to see how this new function works and how it can be beneficial in your code.

For this demo I am going to use the Person.Person table from the AdventureWorks2012 database to demo the SQL functions to generate a full name for creating mailing labels. First, the following example is the old technique to concatenate strings using the + sign (concatenation operator):

    Title + ' ' + FirstName + ' ' + MiddleName + ' ' + LastName as MailingName
FROM Person.Person

As you can see in the screen shot below the MailingName is NULL for any row that has NULL for any one of the name columns. The only rows that have MailingName filled in have a value for all the title, firstname, middlename, and lastname columns. This could be corrected by wrapping ISNULL(column,'') around all the columns in the concatenated field to account for any values having nulls, but that code gets long, messy, and hard to read.

Concat the old way

Below is example syntax is using ISNULL along with the plus sign to concatenate values. The ISNULL function will replace NULL values with the value noted in the second parameter, which in this example is an empty string.

    ISNULL(Title,'') + ' ' + ISNULL(FirstName,'') + ' ' + ISNULL(MiddleName,'') + ' ' + ISNULL(LastName,'') as MailingName
FROM Person.Person

As you can see in the example below, the MailingName is no longer NULL as it replaced the NULL values with an empty string. This achieves the same as using the CONCAT() function, but requires a lot more code and readability.

Concat with ISNULL

The next set of code is using the new CONCAT() function that is in SQL Server 2012 and later versions with a SELECT statement. It replaces NULL values with an empty string of type VARCHAR(1). This SQL statement is much easier to read and write when you need to have NULL code handling in place and generate a single string in a single column with spaces as a separator.

    CONCAT(Title,' ',FirstName,' ',MiddleName,' ',LastName) as MailingName
FROM Person.Person

If you see the results of this, all MailingName values are present, even if they have some of the columns set to NULL.

CONCAT the new way

As you can see this new function is very handy and behaves much different that the old form of concatenation. Instead of evaluating to NULL if any if the columns contain NULL values, the CONCAT() function replaces it with an empty string. This is very useful for coding around NULL values.

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About the author
MSSQLTips author Chad Churchwell Chad Churchwell is a SQL Server professional specializing in High Availability, Disaster Recovery, and Replication.

This author pledges the content of this article is based on professional experience and not AI generated.

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Article Last Updated: 2021-07-21

Comments For This Article

Friday, July 31, 2020 - 3:00:30 AM - Izhar Azati Back To Top (86221)


Wednesday, March 11, 2015 - 12:03:28 PM - Bob Elander Back To Top (36493)

Came in of the Bing and you have provided a valuable solution.  I have a question though I need to combing 2 text fields and a Boolean field as well and am receiving an error. 

Tuesday, March 10, 2015 - 4:33:15 PM - Jeff Page Back To Top (36479)

Just what I was looking for - thanks, Chad!

Saturday, November 29, 2014 - 2:53:04 PM - Athar Anis Back To Top (35432)

I spent several hours trying to figure out why '+' would return NULL as a result. Your article answered it and was up to the point and highly informative.


Wednesday, June 25, 2014 - 1:19:14 PM - Brian Nordberg Back To Top (32400)

Don't forget SET CONCAT_NULL_YIELDS_NULL { ON | OFF }  for those w/o concat function.

Friday, February 14, 2014 - 11:02:08 AM - Terry Carnes Back To Top (29456)

Great extra tip, Phil! That was exactly the question I was asking myself while reading Chad's article. Thank you for addressing it!

Friday, August 30, 2013 - 5:00:07 AM - Madivalappa Patil Back To Top (26544)

This is really very nice article.I appreciate your work.

Thank you very much!!

Thursday, August 22, 2013 - 12:42:11 PM - Phil McDermott Back To Top (26437)

Nice tip! One recommendation: if you include the spacing with the column rather than as a separate item to concatenate, it removes the leading and extra spaces.

SELECT Title, FirstName, MiddleName, LastName,
CONCAT(Title,' ', FirstName,' ', MiddleName,' ', LastName) as MailingName_HasExtraSpaces
CONCAT(Title + ' ', FirstName + ' ', MiddleName + ' ', LastName) as MailingName_NoExtraSpaces,
FROM Person.Person

Thursday, August 22, 2013 - 9:34:27 AM - Jason W Back To Top (26431)

I would think that you would wrap the CONCAT function or the + version with an LTRIM so that when there is no title you are not left with a space for the 1st character. Of course a space at the front of a name for a mailing label might not make that much of a difference.

I think one of the better features of CONCAT is that you don't need to use cast or convert to combine certiain data types.

Thursday, August 22, 2013 - 9:08:50 AM - Owen Overstreet Back To Top (26430)

Great Tip, thank you!

Wednesday, July 24, 2013 - 7:28:45 AM - Awadallah M. Ahmed Back To Top (25973)

Ok! Thank Mr Chad Churchwell .. 

Tuesday, July 23, 2013 - 5:21:30 PM - Jeff Moden Back To Top (25969)

Nice article.  I do have a question, though.  There have been many new features (FORMAT for dates, for example) that actually turn out to be quite aa bit slower than the original brute force methods.  Have you tested to see what the performance and resource usage differencess are between CONCAT and the brute force method on, say, a million rows?

Tuesday, July 23, 2013 - 3:44:56 PM - Chad Churchwell Back To Top (25968)

Thanks Frank, I appreciate the feedback.

Tuesday, July 23, 2013 - 2:49:31 PM - Frank Djabanor Back To Top (25967)

Excellent tip Chad...Another nugget to add to my SQL Server skillset. BTW, great lecture on FileStream & FileTable at JSSUG last week. Thank you.

Tuesday, July 23, 2013 - 9:09:08 AM - Chad Churchwell Back To Top (25962)

When using LTRIM if any of the fields are NULL the whole concatenated string returns NULL.  All LTRIM does is remove leading spaces, really has nothing to do with concatenation. 

Tuesday, July 23, 2013 - 7:39:19 AM - Awadallah M. Ahmed Back To Top (25956)

You can use Ltrim instead of Concat.

Monday, July 22, 2013 - 9:09:08 PM - RLF Back To Top (25946)

BIG time saver...

Nice and simple examples...

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