Create a Trigger is a special kind of stored procedure, that fires when we perform modification on the specific data on the specified table.
Understand with Example
The Tutorial illustrate a example from 'Create After Insert Trigger in SQL'. In this Example, we create a table 'Stu_Table' and 'Stu_Log' using create table statement.
Create Table Stu_Table
Create Table Stu_Table( Stu_Id int, Stu_Name varchar(15),Stu_Class int); |
Create Table Stu_Log
create table stu_log( user_id VARCHAR(15), description VARCHAR(100)); |
Create Trigger Stu_Insert
The Query create a trigger stu_insert on table 'stu_table'. Whenever we perform insert values into a table 'stu_table', an insert trigger is fired and performed for each rows in the table. Once the trigger operation is performed ,this will run the query inside the begin-end statement. The insert into add the records or rows value to the table stu_log.
delimiter $$ CREATE TRIGGER stu_insert AFTER insert ON stu_table FOR EACH ROW
BEGIN
INSERT into stu_log(user_id, description)
VALUES (user(), CONCAT('Insert Student record ',
new.stu_id,' ',new.stu_name,' ',new.stu_class));
END$$
delimiter ;
|
Insert Data Into Stu_Table
insert into stu_table values(1, 'Komal',10); insert into stu_table values(2, 'Ajay',10); insert into stu_table values(3, 'Santosh',10); insert into stu_table values(4, 'Rakesh',10); insert into stu_table values(5, 'Bhau',10); |
Stu_Table
+--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Santosh | 10 | | 4 | Rakesh | 10 | | 5 | Bhau | 10 | +--------+----------+-----------+ |
Stu_Log
+----------------+------------------------------------+ | user_id | description | +----------------+------------------------------------+ | root@localhost | Insert Student record 1 Komal 10 | | root@localhost | Insert Student record 2 Ajay 10 | | root@localhost | Insert Student record 3 Santosh 10 | | root@localhost | Insert Student record 4 Rakesh 10 | | root@localhost | Insert Student record 5 Bhau 10 | +----------------+------------------------------------+ |
If you are facing any programming issue, such as compilation errors or not able to find the code you are looking for.
Ask your questions, our development team will try to give answers to your questions.
Ask Questions? Discuss: Create After Insert Trigger in SQL View All Comments
Post your Comment