Whatever you put between the SQL and the ; will be sent as a query to the database connection that you have open.
You can't use QlikView functions as mixmatch as the database will not understand this syntax and throw the above error back to you. Only use proper syntax that is accepted by your database, in this case, T-SQL for SQL Server.
QlikView functions can be applied in a load statement that uses the SQL statement as a data source like:
A, <- Mixmatch can go in here