An Introduction of User Define Function in SQL
In this article I am going to explain about how to create User Define Function in SQL.
Introduction
In SQL Server there are two type of function which are used to manipulate data in database.
- System define function
- User define function
SQL server provide a list of system define function which are used to manipulate data. These system define function are predefine. We can't change functionality of these system define function. There are many situation where we need a function which performer some specific task according to our need. There function are known as user define function.
There are three types of user define function in SQL Server.
- Scalar- value function
- Simple table-valued function
- Multi-statement table-valued function
Scalar- value function
Scalar- value function is used to return a single value of any T-SQL data type.
Simple table-valued function
Simple table-valued function is used returns a table that's based on single SELECT statement.
Multi-statement table-valued function
Multi-statement table-valued function is used to return a table that's based on multiple statement.
A Statement that create mcnemp table
Statements that insert data in mcnemp table
A Statement that is used to fetch data from mcnemp table
A Statement that creates a function
In this statement we are creating a function.
A Statement that invokes the function
In this statement we use function to fetch data from table.
A Statement that creates an other function
In this statement we are creating a second function.
A Statement that invokes an other function
In this statement we use function to fetch data from table.
