how to create trigger

-- Create table tbl1 (a NUMBER, B VARCHAR2 (20); CREATE UNIQUE INDEX tbl1_pk ON tbl1 (); alter table tbl1 ADD (CONSTRAINT tbl1_pl primary key (a); -- create a music video log, to refresh a single table aggregation VIEW quickly, you must specify the

The failure to create a Trigger caused by MySQL User permissions is embarrassing. MySQL has been in the only-available and incomprehensible stage. I am not very familiar with some of the deeper management, so I have to strengthen it! Recently, in

To be ashamed, MySQL has been in a phase that will only be used and not understood. Even some of the more profound management, are not familiar with, have to strengthen AH!Recently, system testing, using MySQL database, need to create a trigger on a

0. Basic concepts of Triggersa trigger is a special stored procedure that triggers execution when inserting, deleting, or modifying data in a particular table, and it has a finer and more complex data control capability than the standard

Triggers can be created inside Oracle DBA Studio Tools CREATE TRIGGER name Create trigger-creates a new trigger     Syntax CREATE TRIGGER name {before |   After} {event [OR ...] }   on table for each {ROW | STATEMENT} EXECUTE PROCEDURE func

This article mainly introduces the MySQL5 trigger. Every time I demonstrate the actual code, I will use MySQL (the best combination with PHP) the code displayed on the screen of the client is adjusted, mainly by changing the font to Courier, making

1. Create the statement for the trigger: CREATE TRIGGER {before | After} {INSERT | UPDATE | DELETE} On For each ROW -Triggers The code is as follows Copy Code --create Trigger name --on Table name --Trigger

CREATE TRIGGER trigger_name ON { table | view } [ WITH ENCRYPTION ] {{ { FOR | AFTER | INSTEAD OF } { [ INSERT ] [ , ] [ UPDATE ] }[ WITH APPEND ][ NOT FOR REPLICATION ]AS[ { IF UPDATE ( column )[ { AND | OR } UPDATE ( column ) ][ ...n ]| IF (

A trigger is a special type of stored procedure that differs from the stored procedure we described earlier. Triggers are triggered primarily by events that are automatically invoked to execute. Stored procedures can be invoked by the name of the

How do I create a trigger between two tables? Student table: student ID, name, age, department number, department name table: Department number, department name, name, age. How to add a record to the student table is also automatically added to the

A trigger is a special type of stored procedure that differs from the stored procedure we described earlier. Triggers are triggered primarily by events that are automatically invoked to execute. Stored procedures can be invoked by the name of the

SQL trigger Instance 1Definition: What is a trigger? In SQL Server is a certain operation of a table, triggering certain conditions, thus executing a program. A trigger is a special stored procedure. There are three common triggers: Apply to insert,

ViewA view is a virtual table (non-real), which is essentially "getting a dynamic dataset and naming it based on an SQL statement,"Users can only use "name" to get a result set and use it as a table.SELECT *22;temporary table Search1. Create a View--

SQL trigger syntaxSyntaxCreate trigger trigger_nameON {table | view}[With encryption]{{FOR | AFTER | instead of} {[INSERT] [DELETE] [UPDATE]}[With append][Not for replication]AS[{If update (column)[{AND | OR} UPDATE (column)][... N]| IF

Transaction Database open Transaction Command #start transaction 开启事务#Rollback 回滚事务,即撤销指定的sql语句(只能回退insert delete update语句)，回滚到上一次commit的位置#Commit 提交事务，提交未存储的事务#savepoint 保留点 ，事务处理中设置的临时占位符 你可以对它发布回退(与整个事务回退不同) Transaction

MySQL Study Notes _ 10_MySQL Advanced Operations (below) and study notes _ 10_mysql MySQL Advanced Operations (below) V. MySQL pre-processing statements 1. Set the pre-processing stmt and pass a data as the where judgment condition. Prepare stmt

If there are constraints on the trigger table, check these constraints AFTER the INSTEADOF trigger is executed but before the AFTER trigger is executed. If the constraints are damaged, roll back the INSTEADOF trigger operation without executing the

SQL trigger instance 1Definition: What is a trigger? In SQL Server, certain operations on a table trigger certain conditions to execute a program. A trigger is a special stored procedure.There are three common triggers: Insert, Update, and Delete

MySQL study note _ 10_MySQL Advanced Operations (below) MySQL Advanced Operations (below)   V. MySQL pre-processing statements 1. Set the pre-processing stmt and pass a data as the where judgment condition. Prepare stmt from "select * from

ViewA view is a virtual table (not a real one), which is essentially "getting a dynamic dataset from an SQL statement and naming it", which allows the user to get a result set using only "name" and use it as a table.Select *from (