T-SQL and the WHERE LIKE %Parameter% clause

I was trying to write a statement which uses the WHERE LIKE '%text%' clause, but I am not receiving results when I try to use a parameter for the text. For example, this works:

SELECT Employee WHERE LastName LIKE '%ning%'

This would return users Flenning, Manning, Ningle, etc. But this statement would not:

DECLARE @LastName varchar(max)
SET @LastName = 'ning'
SELECT Employee WHERE LastName LIKE '%@LastName%'

No results found. Any suggestions? Thanks in advance.

Solution 1:

It should be:

...
WHERE LastName LIKE '%' + @LastName + '%';

Instead of:

...
WHERE LastName LIKE '%@LastName%'

Solution 2:

The correct answer is, that, because the '%'-sign is part of your search expression, it should be part of your VALUE, so whereever you SET @LastName (be it from a programming language or from TSQL) you should set it to '%' + [userinput] + '%'

or, in your example:

DECLARE @LastName varchar(max)
SET @LastName = 'ning'
SELECT Employee WHERE LastName LIKE '%' + @LastName + '%'

Solution 3:

you may try this one, used CONCAT

WHERE LastName LIKE Concat('%',@LastName,'%')