For checking a uniform condition you may use the CASE construct : CASE « Procedure Function « MySQL Tutorial

Home
MySQL Tutorial
1.Introduction
2.Select Query
3.Database
4.Table
5.Table Join
6.Subquery
7.Insert Update Delete
8.Logic Operator
9.View
10.Data Types
11.Procedure Function
12.Cursor
13.Trigger
14.Date Time Functions
15.Comparison Functions Operators
16.Aggregate Functions
17.Cast Functions Operators
18.Control Flow Functions
19.Encryption Compression Functions
20.Information Functions
21.Math Numeric Functions
22.Miscellaneous Functions
23.String Functions
24.Regular Expressions
25.Data Dictionary
26.MySQL Utilities
27.Privilege
MySQL Tutorial » Procedure Function » CASE 
11.15.1.For checking a uniform condition you may use the CASE construct
CASE case_value
    WHEN when_value THEN statement_list
    [WHEN when_value THEN statement_list...
    [ELSE statement_list]
END CASE

Or:

CASE
    WHEN search_condition THEN statement_list
    [WHEN search_condition THEN statement_list...
    [ELSE statement_list]
END CASE
mysql>

mysql>
mysql>
mysql> DELIMITER //
mysql> CREATE FUNCTION myFunction (delivery_day INT(1)) RETURNS INT(2)
    -> BEGIN
    ->
    -> DECLARE shipping_cost INT(2DEFAULT 0;
    ->
    -> CASE delivery_day
    -> WHEN THEN
    ->         SET shipping_cost = 20;
    -> WHEN THEN
    ->         SET shipping_cost = 15;
    -> WHEN THEN
    ->         SET shipping_cost = 10;
    -> ELSE
    ->         SET shipping_cost = 5;
    -> END CASE;
    -> RETURN shipping_cost;
    ->
    -> END
    -> //
Query OK, rows affected (0.00 sec)

mysql> DELIMITER ;
mysql>
mysql> select myFunction(1);
+---------------+
| myFunction(1|
+---------------+
|            20 |
+---------------+
row in set (0.00 sec)

mysql>
mysql> select myFunction(2);
+---------------+
| myFunction(2|
+---------------+
|            15 |
+---------------+
row in set (0.00 sec)

mysql>
mysql> select myFunction(3);
+---------------+
| myFunction(3|
+---------------+
|            10 |
+---------------+
row in set (0.00 sec)

mysql>
mysql> drop function myFunction;
Query OK, rows affected (0.00 sec)

mysql>
mysql>
11.15.CASE
11.15.1.For checking a uniform condition you may use the CASE construct
11.15.2.CASE Statement with Condition Checks
11.15.3.Using CASE WHEN statement in a procedure
11.15.4.Using CASE WHEN condition statement in a procedure
11.15.5.CASE WHEN with ELSE
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.