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MariaDB/MySQL Stored Language Examples

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 19 Mar 2020 17:53:29 +0000

MariaDB/MySQL Stored Language is called SQL/PSM.
There are 4 different types of Stored Language: Stored Procedures, Stored Functions, Triggers and Events.

Example 1

oli.sennhauser@fromdual.com (Oli Sennhauser) — Fri, 09 Dec 2011 10:07:51 +0000

CREATE TABLE `order` (
 id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY
, name VARCHAR(64) NOT NULL
) ENGINE = InnoDB;

INSERT INTO `order` VALUES
 (NULL, 'Test order 1')
, (NULL, 'Test order 2')
, (NULL, 'Test order 3');


CREATE TABLE pos (
 id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY
, order_id INT UNSIGNED NOT NULL
, name VARCHAR(64) NOT NULL
, amount SMALLINT NOT NULL
, price DECIMAL (6,2) NOT NULL
, status TINYINT NULL
) ENGINE = InnoDB;

INSERT INTO pos VALUES
 (null, 1, 'Schrauben', 50, 0.10, 0)
, (null, 1, 'Muttern', 50, 0.10, 0)
, (null, 2, 'Nägel', 1000, 0.05, 1);


CREATE TABLE pos_shadow LIKE pos;
ALTER TABLE pos_shadow ENGINE = MEMORY;
INSERT INTO pos_shadow SELECT * FROM pos;

delimiter //

CREATE TRIGGER upd BEFORE UPDATE ON pos
FOR EACH ROW
BEGIN
 UPDATE pos_shadow AS p
 JOIN `order` AS o ON o.id = p.order_id and o.id = NEW.order_id
 SET status = 1
 WHERE o.id = 1;
END;
//

delimiter ;

SELECT o.name, p.name, p.amount, p.price, (p.amount*p.price) AS total, p. status
 FROM `order` AS o
 JOIN pos_shadow AS p ON p.order_id = o.id
;

UPDATE pos AS p
 JOIN `order` AS o ON o.id = p.order_id AND o.id = 1
 SET p.status = 1, p.order_id = 1
 where o.id = 1;

SELECT o.name, p.name, p.amount, p.price, (p.amount*p.price) AS total, p. status
 FROM `order` AS o
 JOIN pos AS p on p.order_id = o.id
;

How good is MySQL INSERT TRIGGER performance

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 03 Aug 2011 17:08:36 +0000

Abstract: In this article we discuss how big is the performance impact of MySQL TRIGGERs compared to application side logging (with INSERT) into a MySQL table.

MySQL logon and logoff trigger for auditing

oli.sennhauser@fromdual.com (Oli Sennhauser) — Fri, 10 Dec 2010 23:23:51 +0000

A while ago I did some research about MySQL audit functionality and logon a and logoff triggers. MySQL and MariaDB provide a logon trigger in the form of the init_connect variable but no logoff trigger where most of the work for auditing would be done. When we would have a logoff trigger we could track the login and possibility some activity of a user and implement auditing functionality.

MySQL Server Error Codes and Messages 1450 - 1499

oli.sennhauser@fromdual.com (Oli Sennhauser) — Mon, 06 Dec 2010 11:51:27 +0000

1400 - 1449 1500 - 1549

Error: 1450 SQLSTATE: HY000 (ER_FORBID_SCHEMA_CHANGE)

MySQL Server Error Codes and Messages 1400 - 1449

oli.sennhauser@fromdual.com (Oli Sennhauser) — Mon, 06 Dec 2010 11:50:26 +0000

1350 - 1399 1450 - 1499

Error: 1400 SQLSTATE: XAE09 (ER_XAER_OUTSIDE)

MySQL Server Error Codes and Messages 1350 - 1399

oli.sennhauser@fromdual.com (Oli Sennhauser) — Mon, 06 Dec 2010 11:49:09 +0000

1300 - 1349 1400 - 1449

Error: 1350 SQLSTATE: HY000 (ER_VIEW_SELECT_CLAUSE)

Materialized Views with MySQL

oli.sennhauser@fromdual.com (Oli Sennhauser) — Sat, 13 Mar 2010 13:55:05 +0000

MySQL logon trigger

oli.sennhauser@fromdual.com (Oli Sennhauser) — Fri, 25 May 2007 17:06:00 +0000

With MySQL 5.0 the database provides trigger functionality on INSERT, REPLACE, UPDATE and DELETE.