mysql trigger before update

Database trigger details bitsCN. com1 introduction Like the stored procedure, Mysql triggers are embedded into a mysql program. The trigger is a new function of mysql5. Currently, the online Fengchao system, Beidou system, and Columbus system use

1 Introduction Like the stored procedure, Mysql triggers are embedded into a mysql program. The trigger is a new function of mysql5. Currently, the online fengchao system, Beidou system, and Columbus system use the database of mysql5.0.45. Many

ConventionsandStyles convention and programming style every time I want to demonstrate the actual code, I will adjust the code displayed on the screen of the mysql client and change the font to Courier, make them look different from common text (let

Why use a trigger? Advantages of triggers 1. Trigger's "automatic"For programmers, the trigger is invisible, but he does. If no trigger is needed, when you update the name field of the user table, you need to write code to update redundant fields in

Q: What is a trigger?A:A trigger is a database object that is related to a table, fires when a condition is met, and executes a collection of statements defined in the trigger.650) this.width=650; "Src=" http://images2015.cnblogs.com/blog/1113510/201

1. TRIGGER introduction trigger is a mysql TRIGGER. When a trigger is created, it monitors specific events. When a TRIGGER is triggered, an object is activated to process trigger_stmt, that is, the statement to be executed. For example, when you add

A trigger is a special kind of stored procedure that triggers execution when inserting, deleting, or modifying data in a particular table, which has finer and more complex data control than the standard functionality of the database itself.Database

MySQL trigger and mysql trigger MySQL from 5.0.2 version to support the function of the trigger, this blog to introduce the trigger, mysql version: mysql-5.7.19.  What is a trigger? A trigger is a database object related to tables. It is triggered

One, what triggers1, personal understandingThe function of the trigger is to achieve synchronization between the two libraries, that is, the operation of library A and so on in the operation of library B, you can create a change on the table a

One, the advantages of the trigger1, the " automatic " of the triggerTo the programmer, the trigger is not visible, but he did do things, if you do not use a trigger, you update the user table name field, you also write code to update other tables