LOWER (Transact-SQL)

character_expression

Is an expression of character or binary data. character_expression can be a constant, variable, or column. character_expression must be of a data type that is implicitly convertible to varchar. Otherwise, use CAST to explicitly convert character_expression.

varchar or nvarchar

The following example uses the LOWER function, the UPPER function, and nests the UPPER function inside the LOWER function in selecting product names that have prices between $11 and $20.

USE AdventureWorks2008R2;
GO
SELECT LOWER(SUBSTRING(Name, 1, 20)) AS Lower, 
   UPPER(SUBSTRING(Name, 1, 20)) AS Upper, 
   LOWER(UPPER(SUBSTRING(Name, 1, 20))) As LowerUpper
FROM Production.Product
WHERE ListPrice between 11.00 and 20.00;
GO

Here is the result set.

Lower Upper LowerUpper

--------------------- --------------------- --------------------

minipump MINIPUMP minipump

taillights - battery TAILLIGHTS - BATTERY taillights - battery

(2 row(s) affected)

Reference