SQL Server/T-SQL/Trigger/Trigger after — различия между версиями

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Текущая версия на 10:20, 26 мая 2010

Controlling DML Triggers Based on Modified Columns

 
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
----------- ---------- ---------- ------------ ----------------------- ---------- -------------------- -----------
          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



Creating an AFTER DML Trigger

 
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
----------- ---------- ---------- ------------ ----------------------- ---------- -------------------- -----------
          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
----------- -------------------- -----------------------
         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>