A function must return a result. So that is also called a function that returns a result or a value. When we create it a function must specify a value type that will return a value.
• Functions only work with select statements.
• Functions can be used anywhere in SQL, such as AVG, COUNT, SUM, MIN, DATE and so on with select statements.
• Functions compile every time.
• Functions must return a value or result.
• Functions only work with input parameters.
• Try and catch statements are not used in functions.
Function Types:
The following is the function list in SQL Server databases.
SQL Server contains the following aggregates functions: