SQL Server/T-SQL/Trigger/Trigger after
Controlling DML Triggers Based on Modified Columns
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4> 5> CREATE TABLE employee( 6> id INTEGER NOT NULL PRIMARY KEY, 7> first_name VARCHAR(10), 8> last_name VARCHAR(10), 9> salary DECIMAL(10,2), 10> start_Date DATETIME, 11> region VARCHAR(10), 12> city VARCHAR(20), 13> managerid INTEGER 14> ); 15> GO 1> INSERT INTO employee VALUES (1, "Jason" , "Martin", 5890,"2005-03-22","North","Vancouver",3); 2> GO 1> INSERT INTO employee VALUES (2, "Alison", "Mathews",4789,"2003-07-21","South","Utown",4); 2> GO 1> INSERT INTO employee VALUES (3, "James" , "Smith", 6678,"2001-12-01","North","Paris",5); 2> GO 1> INSERT INTO employee VALUES (4, "Celia" , "Rice", 5567,"2006-03-03","South","London",6); 2> GO 1> INSERT INTO employee VALUES (5, "Robert", "Black", 4467,"2004-07-02","East","Newton",7); 2> GO 1> INSERT INTO employee VALUES (6, "Linda" , "Green" , 6456,"2002-05-19","East","Calgary",8); 2> GO 1> INSERT INTO employee VALUES (7, "David" , "Larry", 5345,"2008-03-18","West","New York",9); 2> GO 1> INSERT INTO employee VALUES (8, "James" , "Cat", 4234,"2007-07-17","West","Regina",9); 2> GO 1> INSERT INTO employee VALUES (9, "Joan" , "Act", 6123,"2001-04-16","North","Toronto",10); 2> GO 1> 2> select * from employee; 3> GO id first_name last_name salary start_Date region city managerid
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1 Jason Martin 5890.00 2005-03-22 00:00:00.000 North Vancouver 3
2 Alison Mathews 4789.00 2003-07-21 00:00:00.000 South Utown 4
3 James Smith 6678.00 2001-12-01 00:00:00.000 North Paris 5
4 Celia Rice 5567.00 2006-03-03 00:00:00.000 South London 6
5 Robert Black 4467.00 2004-07-02 00:00:00.000 East Newton 7
6 Linda Green 6456.00 2002-05-19 00:00:00.000 East Calgary 8
7 David Larry 5345.00 2008-03-18 00:00:00.000 West New York 9
8 James Cat 4234.00 2007-07-17 00:00:00.000 West Regina 9
9 Joan Act 6123.00 2001-04-16 00:00:00.000 North Toronto 10
1> 2> 3> 4> CREATE TRIGGER trg_employee 5> ON employee 6> AFTER UPDATE 7> AS 8> IF UPDATE(first_Name) 9> BEGIN 10> PRINT "Updates to first name require DBA involvement." 11> ROLLBACK 12> END 13> GO 1> 2> UPDATE employee 3> SET first_Name = "R" 4> WHERE ID = 10 5> 6> drop table trg_employee 7> GO Updates to first name require DBA involvement. Msg 3609, Level 16, State 1, Server BCE67B1242DE45A\SQLEXPRESS, Line 2 The transaction ended in the trigger. The batch has been aborted. 1> drop trigger trg_employee 2> GO 1> drop table employee; 2> GO
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Creating an AFTER DML Trigger
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4> 5> CREATE TABLE employee( 6> id INTEGER NOT NULL PRIMARY KEY, 7> first_name VARCHAR(10), 8> last_name VARCHAR(10), 9> salary DECIMAL(10,2), 10> start_Date DATETIME, 11> region VARCHAR(10), 12> city VARCHAR(20), 13> managerid INTEGER 14> ); 15> GO 1> INSERT INTO employee VALUES (1, "Jason" , "Martin", 5890,"2005-03-22","North","Vancouver",3); 2> GO 1> INSERT INTO employee VALUES (2, "Alison", "Mathews",4789,"2003-07-21","South","Utown",4); 2> GO 1> INSERT INTO employee VALUES (3, "James" , "Smith", 6678,"2001-12-01","North","Paris",5); 2> GO 1> INSERT INTO employee VALUES (4, "Celia" , "Rice", 5567,"2006-03-03","South","London",6); 2> GO 1> INSERT INTO employee VALUES (5, "Robert", "Black", 4467,"2004-07-02","East","Newton",7); 2> GO 1> INSERT INTO employee VALUES (6, "Linda" , "Green" , 6456,"2002-05-19","East","Calgary",8); 2> GO 1> INSERT INTO employee VALUES (7, "David" , "Larry", 5345,"2008-03-18","West","New York",9); 2> GO 1> INSERT INTO employee VALUES (8, "James" , "Cat", 4234,"2007-07-17","West","Regina",9); 2> GO 1> INSERT INTO employee VALUES (9, "Joan" , "Act", 6123,"2001-04-16","North","Toronto",10); 2> GO 1> 2> select * from employee; 3> GO id first_name last_name salary start_Date region city managerid
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1 Jason Martin 5890.00 2005-03-22 00:00:00.000 North Vancouver 3
2 Alison Mathews 4789.00 2003-07-21 00:00:00.000 South Utown 4
3 James Smith 6678.00 2001-12-01 00:00:00.000 North Paris 5
4 Celia Rice 5567.00 2006-03-03 00:00:00.000 South London 6
5 Robert Black 4467.00 2004-07-02 00:00:00.000 East Newton 7
6 Linda Green 6456.00 2002-05-19 00:00:00.000 East Calgary 8
7 David Larry 5345.00 2008-03-18 00:00:00.000 West New York 9
8 James Cat 4234.00 2007-07-17 00:00:00.000 West Regina 9
9 Joan Act 6123.00 2001-04-16 00:00:00.000 North Toronto 10
1> 2> 3> -- Track all Inserts, Updates, and Deletes 4> CREATE TABLE EmployeeAudit 5> (ID int NOT NULL , 6> first_name char(20) NOT NULL, 7> dt datetime ) 8> GO 1> 2> CREATE TRIGGER trg_uid_Audit 3> ON employee 4> AFTER INSERT, DELETE 5> AS 6> SET NOCOUNT ON 7> -- Inserted rows 8> INSERT EmployeeAudit(ID, first_name,dt) 9> SELECT DISTINCT i.ID, i.first_name, GETDATE() 10> FROM inserted i 11> -- Deleted rows 12> INSERT EmployeeAudit 13> (ID, first_name,dt) 14> SELECT d.ID, d.first_name, GETDATE() 15> FROM deleted d 16> GO 1> 2> -- Insert a new row 3> INSERT employee 4> (ID, first_name) 5> VALUES (16, "A") 6> GO 1> -- Delete a row 2> DELETE employee 3> WHERE ID = 6 4> GO 1> -- Check the audit table 2> SELECT * FROM EmployeeAudit 3> GO ID first_name dt
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16 A 2007-10-20 00:37:40.743
6 Linda 2007-10-20 00:37:40.773
1> 2> 3> 4> drop table EmployeeAudit 5> GO 1> drop trigger trg_uid_Audit 2> GO 1> drop table employee; 2> GO 1>
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