You can achieve case sensitive comparison of strings in queries by converting strings to the binary or varbinary datatype. You cannot achieve this with simple string comparisons if you have installed SQL Server with the case-insensitive option. This technique becomes handy when used to compare data like passwords. For example, to choose a record from table X whose column1 value is ‘ABCD’ but not select a record with the value ‘abcd’, you could use this query:
Select * from X where convert(varbinary, column1) = convert(varbinary, 'ABCD')