Sql server ___________session_20(ddl triggers)
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The document discusses different types of triggers in SQL Server including: - DDL triggers that fire on database events like create, alter, and drop operations. - INSTEAD OF triggers that intercept DML operations like DELETE and allow modifying or replacing the action. - Nested triggers where one trigger firing can initiate another trigger. - Disabling triggers on a specific table or for all triggers.
![CREATETRIGGER [name of
trigger]
ON [scope (database|server)]
FOR [event]
As
--Trigger definition here…](https://image.slidesharecdn.com/sqlserversession20ddltriggers-151009201558-lva1-app6892/85/Sql-server-___________session_20-ddl-triggers-2-320.jpg)
Sql server ___________session_20(ddl triggers)
- 2. CREATETRIGGER [name of trigger] ON [scope (database|server)] FOR [event] As --Trigger definition here…
- 3. Create table back_up ( actions varchar(20), action_date datetime ) create trigger ddl_trg on database for create_table(,alter_table,drop_table) as declare @ac varchar(20); SELECT top 1 @ac = name FROM sys.tables insert into back_up values(@ac+' table has been created', getdate()) print 'table created';
- 4. create table std ( id int, name varchar(20) ) select * from back_up
- 5. create trigger ddl_db on all server for create_database as declare @ac varchar(20); declare @dt varchar(30); SELECT top 100 percent @ac = name FROM sys.databases; set @dt=getdate(); print @ac+' database has been created on '+ @dt;
- 7. ALTERTABLE Employee_Test {ENABLE|DISBALE}TRIGGER ALL ALTERTABLE Employee_Test DISABLE TRIGGER trgAfterDelete
- 8. Triggers are said to be nested if one trigger action initiates another trigger. create trigger trgNestedInsert on Employee_Test_Audit for insert as print 'NESTED INSERT trigger fired';
- 9. These can be used as an interceptor for anything that anyone tried to do on our table or view. If you define an Instead Of trigger on a table for the Delete operation, they try to delete rows, and they will not actually get deleted (unless you issue another delete instruction from within the trigger) INSTEAD OFTRIGGERS can be classified further into three types as:- (a) INSTEAD OF INSERTTrigger. (b) INSTEAD OF UPDATETrigger. (c) INSTEAD OF DELETETrigger.
- 10. CREATE TRIGGER trgInsteadOfDelete ON Employee_Test INSTEAD OF DELETE AS declare @emp_id int; declare @emp_name varchar(100); declare @emp_sal int; select @emp_id=d.Emp_ID from deleted d; select @emp_name=d.Emp_Name from deleted d; select @emp_sal=d.Emp_Sal from deleted d; BEGIN if(@emp_sal>1200) begin RAISERROR('Cannot delete where salary > 1200',16,1); ROLLBACK; end else begin delete from Employee_Test where Emp_ID=@emp_id; COMMIT; insert into Employee_Test_Audit(Emp_ID,Emp_Name,Emp_Sal,Audit_Action,Audit_Timestamp) values(@emp_id,@emp_name,@emp_sal,'Deleted -- Instead Of DeleteTrigger.',getdate()); PRINT 'Record Deleted -- Instead Of DeleteTrigger.' end