Create a scalar-valued function that returns the total Billing amount due : function « Procedure Function « SQL Server / T-SQL Tutorial

6> create table Billings (
7>     BankerID           INTEGER,
8>     BillingNumber      INTEGER,
9>     BillingDate        datetime,
10>     BillingTotal       INTEGER,
11>     TermsID            INTEGER,
12>     BillingDueDate     datetime ,
13>     PaymentTotal       INTEGER,
14>     CreditTotal        INTEGER
15>
16> );
17> GO
1>
2> INSERT INTO Billings VALUES (1, 1, '2005-01-22', 165, 1,'2005-04-22',123,321);
3> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (2, 2, '2001-02-21', 165, 1,'2002-02-22',123,321.);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (3, 3, '2003-05-02', 165, 1,'2005-04-12',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (4, 4, '1999-03-12', 165, 1,'2005-04-18',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (5, 5, '2000-04-23', 165, 1,'2005-04-17',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (6, 6, '2001-06-14', 165, 1,'2005-04-18',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (7, 7, '2002-07-15', 165, 1,'2005-04-19',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (8, 8, '2003-08-16', 165, 1,'2005-04-20',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (9, 9, '2004-09-17', 165, 1,'2005-04-21',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (0, 0, '2005-10-18', 165, 1,'2005-04-22',123,321);
2> GO

(1 rows affected)
1>
2> CREATE FUNCTION fnBalanceDue()
3>     RETURNS money
4> BEGIN
5>     RETURN (SELECT SUM(BillingTotal - PaymentTotal - CreditTotal)
6>             FROM Billings
7>             WHERE BillingTotal - PaymentTotal - CreditTotal > 0)
8> END
9> GO
1>
2>
3>
4> --A script that invokes the function
5> PRINT 'Current outstanding balance is: $' +
6>        CONVERT(varchar,dbo.fnBalanceDue(),1)
7>
8>
9>
10> drop FUNCTION fnBalanceDue;
11> GO

1>
2>
3> drop table Billings;
4> GO
1>

21.2.function
	21.2.1.	The syntax for creating a multi-statement table-valued function
	21.2.2.	The syntax for creating a scalar-valued function
	21.2.3.	The syntax for creating a simple table-valued function
	21.2.4.	The syntax of the ALTER FUNCTION statement for a scalar valued function
	21.2.5.	The syntax for altering a simple table-valued function
	21.2.6.	The syntax for altering a multi-statement table-valued function
	21.2.7.	Call user-defined function in where clause
	21.2.8.	Call two user-defined functions in a select statement
	21.2.9.	Function WITH SCHEMABINDING
	21.2.10.	Multistatement Table-Valued Functions
	21.2.11.	Pass a declared variable to a function
	21.2.12.	Return TOP 100 PERCENT WITH TIES from a function
	21.2.13.	Get the 3 employees with the most RegionPlace
	21.2.14.	Use function as a view
	21.2.15.	Create a scalar-valued function that returns the total Billing amount due
	21.2.16.	Invoke the scalar-valued function
	21.2.17.	A SELECT statement that uses the function in a join operation
	21.2.18.	Use function to wrap a long sql statement
	21.2.19.	Query a table returned from a function