New built-in function CONCAT_WS() in SQL Server vNext (2018)

In my previous posts I discussed new Functions introduced in SQL Server vNext (or 2018), like STRING_AGG() , TRIM() , TRANSLATE() .

Here in this post I’ll discuss about one more new function i.e. CONCAT_WS() , here “_WS” means “With Separator”.

This is very similar to the existing CONCAT() function introduced back in SQL Server 2012, which concatenates a variable number of arguments or string values.

The difference is the new function CONCAT_WS() accepts a delimiter specified as the 1st argument, and thus there is no need to repeat the delimiter after very String value like in CONCAT() function.

Also the new CONCAT_WS() function takes care of NULL values and do not repeat the delimiter, which you can see in 2nd example below.

Syntax: CONCAT_WS ( separator, argument1, argument1 [, argumentN]… ) > Example #1:

With CONCAT_WS() we will use the delimiter just once and it concatenates the names separated by ‘-‘, and do not repeat the hyphen where the middle name is NULL.

USE [AdventureWorks2014]
GO
SELECT TOP 10
CONCAT_WS(' - ', FirstName, MiddleName, LastName) as FullName,
FirstName, MiddleName, LastName
FROM [Person].[Person]

> Example #2:

With CONCAT() the delimiter needs to be used after every argument, it concatenates the names separated by ‘-‘, do repeats the hyphen where the middle name is NULL.

SELECT TOP 10
CONCAT(FirstName, ' - ', MiddleName, ' - ', LastName) as FullName,
FirstName, MiddleName, LastName
FROM [Person].[Person]