Using variable in SQL LIKE statement

Question

I\'ve got a sproc (MSSQL 2k5) that will take a variable for a LIKE claus like so:

DECLARE @SearchLetter2 char(1)
SET @SearchLetter = \'t\'
SET @SearchLetter2         


        

Answer 1

If you are using a Stored Procedure:

ALTER PROCEDURE <Name>
(
    @PartialName VARCHAR(50) = NULL
)

SELECT Name 
    FROM <table>
    WHERE Name LIKE '%' + @PartialName + '%'

Answer 2

But in my opinion one important thing.

The "char(number)" it's lenght of variable.

If we've got table with "Names" like for example [Test1..Test200] and we declare char(5) in SELECT like:

DECLARE @variable char(5)
SET @variable = 'Test1%'
SELECT * FROM table WHERE Name like @variable

the result will be only - "Test1"! (char(5) - 5 chars in lenght; Test11 is 6 )

The rest of potential interested data like [Test11..Test200] will not be returned in the result.

It's ok if we want to limit the SELECT by this way. But if it's not intentional way of doing it could return incorrect results from planned ( Like "all Names begining with Test1..." ).

In my opinion if we don't know the precise lenght of a SELECTed value, a better solution could be something like this one:

DECLARE @variable varchar(max)
SET @variable = 'Test1%'
SELECT * FROM <table> WHERE variable1 like @variable

This returns (Test1 but also Test11..Test19 and Test100..Test199).

Answer 3

Joel is it that @SearchLetter hasn't been declared yet? Also the length of @SearchLetter2 isn't long enough for 't%'. Try a varchar of a longer length.