MYSQL PL/SQL

a set SQL statement Set, fast, only the first execution needs to be compiled and optimized steps, subsequent calls can be directly executed

S Ample:

DROP PROCEDURE IF EXISTS ' Proc_adder ';

DELIMITER &&

CREATE definer= ' root ' @ ' localhost ' PROCEDURE ' proc_adder ' (in a int, in B int, out sum int)

BEGIN

DECLARE c int;

/* DECLARE C int DEFAULT ten* /

If a is null and then set a = 0;

End If;

If B is null and then set B = 0;

End If;
Set sum = a + b;

END

&&

DELIMITER;

Description

Definer : created by

DECLARE : Defining variables

SET : assigns a variable

SELECT... into The statement assigns a value to the variable as follows:

SELECT col_name[,... ] into var_name[,... ]  

From table_name wehre condition

The default statement terminator in MySQL is a semicolon (; ). The SQL statement in the stored procedure requires a semicolon (; ) to end. To avoid conflicts, first use "DELIMITER &&" to set MySQL 's terminator to && . And finally the "DELIMITER;" to restore the Terminator to the component number. This is the same as when you create a trigger.

Common syntax:

IF:

IF type = 0 Then

Set c = ' param is 0 ';

ELSEIF type = 1 Then

Set c = ' param is 1 ';

ELSE

Set c = ' param is others, not 0 or 1 ';

END IF;

Case:

Case Type

When 0 Then

Set c = ' param is 0 ';

When 1 Then

Set c = ' param is 1 ';

ELSE

Set c = ' param is others, not 0 or 1 ';

END case;

while :

DECLARE I int;

DECLARE s int;

SET i = 0;

SET s = 0;

While I <= n do

Set S = s + i;

Set i = i + 1;

END while;

This article is from the "Small Yard Farm" blog, please make sure to keep this source http://daoqingyu.blog.51cto.com/5185063/1950443

MYSQL PL/SQL