why use trigger in sql

Triggers can do a lot of things, but it also brings a lot of problems. The right use is to use it at the right time and not to use it when it is inappropriate.Some common uses for triggers are as follows:[1] Elastic referential integrity: implements

SQL Server trigger details, SQL Server trigger Trigger is a method provided by SQL server to programmers and data analysts to ensure data integrity. It is a special stored procedure related to table events, its execution is not called by a program,

The previous document on triggers is provided. Triggers are important to SQL Server. SQL Server: Basic trigger documentation SQLServer Database Development trigger application A trigger is a special stored procedure, similar to the event functions

A special stored procedure that is automatically executed when a trigger inserts, updates, or deletes a table. Triggers are generally used for constraints with more complex check constraints. The difference between a trigger and a Common Stored

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

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

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,

Today colleagues let me see a trigger why always error, when the execution DML statement trigger trigger, will be reported ORA-04091 errors: ora-04091:table xxxx is mutating, trigger/function might not see it. The corresponding Chinese error prompt

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

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