mysql trigger tutorial

The following two examples are from:Http://www.cnblogs.com/nicholas_f/archive/2009/09/22/1572050.htmlThe actual measurement is valid, but the original post delimiter is not correct, so modify it slightly.Where old means tab2 (passive trigger), new represents TAB1 (active, external application executes INSERT statement in this table)Example 1:Create two tables to add one record in one table, and another to add a record:DROP TABLE IF EXISTS tab1;CREATE

Tags: mysql val let div drop delete font update name DROP TRIGGER IF EXISTST_a_b;/*Delete Trigger*/ CREATE TRIGGERT_a_b/*Create a trigger T_a_b*/ AfterINSERT onA/*identification trigger time, value is before or after;*/ /*Thus, there are 6

The event scheduler can sometimes also be called a temporary trigger (temporal triggers),Because the event scheduler performs certain tasks based on a specific time period trigger, the trigger (Triggers) is triggered based on events generated by a table, and the difference is here.Before you can use this feature, you must ensure that Event_scheduler is turned on

MySQL synchronizes two tables with a triggerCurrently, the test is successful locally.Suppose that the local two databases A and b,a have table table1 (ID, Val) under B with table table2 (ID, Val)Assume that you want data to be updated in the Table1, and the data in Table2 is updated synchronously.Code:DELIMITER $$CREATE/*[definer = {User | Current_User}]*/TRIGGER ' a '. '

Trigger (Trigger): Monitors a situation and triggers an action.Trigger creation Syntax Four elements:1. Monitoring location (table) 2. Monitoring Events (Insert/update/delete) 3. Trigger Time (After/before) 4. Trigger Event ( Insert/update/delete)Grammar:Create Trigger Trig

Tags: style blog io color ar for SP div on--InsertDELIMITER $$ Use' testdatabase ' $$DROP TRIGGER /*!50032 IF EXISTS*/' Trigger_xxx_insert ' $$CREATE /*!50017 definer = ' root ' @ '% '*/ TRIGGER' Trigger_xxx_insert ' afterINSERT on' tb_xxx ' forEach ROWBEGIN DECLARENewStatusINT; SETNewStatus=NEW ' Status '; --omit do something END; $ $DELIMITER;--UpdateDELIMITER $$ Use' testdatabase ' $$DROP

Label:Run under the Mysql.exe.If yes, it may be necessary to add a definition DELIMITER//It means to tell MySQL that the statement ended after encountering//symbols.Otherwise, if MySQL encounters a semicolon, it thinks the statement is over and the trigger code is not finished.Mysql> DELIMITER//mysql> CREATE

‘PRIMARY‘Mysql>Mysql> Select * FromT_bluerosehero;+----+------+|Id|Col|+----+------+| 1 | |+----+------+1 Row in Set (0.00 sec) mysql> OrMysql>Delimiter//Mysql> Create TriggerTr_t_bluerosehero_bi beforeInsert OnT_bluerosehero- ForEach row- Begin-DeclareIInt;-IfNew.col>30 Then-Insert IntoXxxxValues(1);-End If;- End;- //Query OK,0Rows Affected (0.06Se

MySQL stored procedures and function stored proceduresDownloadDemoMysql> delimiter// --here//for modifying the default delimiter;mysql> CREATE PROCEDURE simpleproc (out param1 INT) beginThis calls the trial callMysql> call Simpleproc (@a); Mysql> Select @a;Function DemoParameter does not have input/output parametersmysql> CREATE FUNCTION Hello (S CHAR ())

Label:#表 ( jc_shop_product ) has a status value-whether the shelves (On_sale) to shelves (0) into the shelf (1) and set the shelf time (on_sale_time) Drop trigger if exists update_on_sale_time_of_product; Delimiter// CREATE TRIGGER update_on_sale_time_of_product before update on jc_shop_product for each ROW BEGIN IF old.on_sale=0 new.on_sale=1 then SET new.on_sale_time=now (); END IF; END; delimiter; A

time, but for us is only a blink of an eye, as long as the separation of two execution time is enough. A little bit of personal experience, hope to help everyone. Individual environment yo often check show variables like '%event_scheduler% '; make sure this database permission is already open OK To open the Event_scheduler SQL command:SET GLOBAL event_scheduler = on;SET @ @global. Event_scheduler = on;SET GLOBAL event_scheduler = 1;SET @ @global. Event_scheduler = 1;Instead, close the Event_sc

MySQL can implement timed triggering functions, such as what to do with a MySQL database at a certain time, or how often to do what work.The second case is widely used, for example, I would like to check my data information every day, more than one months of useless information to clear up to make room for other storage data to use, or a period of time to update the data and so on.The following discussion o

ROWBEGIN if Not exists(Select * fromWechat.demowhereWechat.demo.id=Old.id andWechat.demo. ' Name '=New.name andWechat.demo. ' Password '=New.password) Then UpdateWechat.demoSetWechat.demo. ' Name '=New.name, Wechat.demo. ' Password '=New.passwordwhereWechat.demo.id=old.id;End if; END; CREATE TRIGGERup afterUPDATE onWechat.demo forEach ROWBEGIN if Not exists(Select * fromVaccine.demowhereVaccine.demo.id=New.id andVaccine.demo. ' Name '=New.name andVaccine.demo. ' Password '=New.password) Th

This article mainly introduces the basic learning tutorial of MySQL triggers, including the basic knowledge of trigger creation and management! For more information, see 0. basic concepts of triggersA trigger is a special stored procedure that triggers execution when inserting, deleting, or modifying data in a specific

MYSQL Tutorial: There are many reasons for running multiple MySQL servers to run multiple servers. for example, the above mentioned restriction can bypass the maximum file descriptor, there are also version tests and dedicated services. Running multiple servers is much more complex than running a single server. pay attention to the following issues: When install

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PHP connection and Operation MySQL database basic tutorial, MySQL basic tutorial Start from here What is my blog, background database? Yes, it is MySQL, the server side of the script is PHP, the entire framework uses WordPress. PHP and