quote:

---

Function Invocation
Scalar-valued functions may be invoked where scalar expressions are used, including computed columns and CHECK constraint definitions. When invoking scalar-valued functions, at minimum use the two-part name of the function.

[database_name.]owner_name.function_name ([argument_expr][,...])

If a user-defined function is used to define a computed column, the function's deterministic quality also defines whether an index may be created on that computed column. An index can be created on a computed column that uses a function only if the function is deterministic. A function is deterministic if it always returns the same value, given the same input.

Table-valued functions can be invoked using a single part name.

[database_name.][owner_name.]function_name ([argument_expr][,...])

System table functions that are included in Microsoft® SQL Server™ 2000 need to be invoked using a '::' prefix before the function name.

SELECT *
FROM ::fn_helpcollations()

Transact-SQL errors that cause a statement to be stopped and then continued with the next statement in a stored procedure are treated differently inside a function. In functions, such errors will cause the function execution to be stopped. This in turn will cause the statement that invoked the function to be stopped.

---