Changing Strings to Lower Case
The Transact SQL Lower function is used to convert strings to all lower case. For example, the following statement returns a lower case ProductName from the Products table of the Northwind sample database:
SELECT LOWER(ProductName) as ProductName FROM Products
Changing Strings to Upper Case
The Transact SQL Upper function is used to convert strings to all upper case (i.e. capitals). For example, the following statement returns an upper case ProductName from the Products table of the Northwind sample database:
SELECT UPPER(ProductName) as ProductName FROM Products
Changing the Case of Database Table Columns
If you need to permanently change the case of text within specific database columns, then a SQL statement like the following can be used:
UPDATE Products SET ProductName = UPPER(ProductName)
A WHERE clause could also be used if only certain rows needed to be changed.