mysql触发器实例 删除触发器

mysql> CREATE TABLE Employee( //创建测试用的数据表

-> id int,

-> first_name VARCHAR(15),

-> last_name VARCHAR(15),

-> start_date DATE,

-> end_date DATE,

-> salary FLOAT(8,2),

-> city VARCHAR(10),

-> description VARCHAR(15)

-> );

Query OK, 0 rows affected (0.03 sec)

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values (1,'Jason', 'Martin', '19960725', '20060725', 1234.56, 'Toronto', 'Programmer');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(2,'Alison', 'Mathews', '19760321', '19860221', 6661.78, 'Vancouver','Tester');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(3,'James', 'Smith', '19781212', '19900315', 6544.78, 'Vancouver','Tester');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(4,'Celia', 'Rice', '19821024', '19990421', 2344.78, 'Vancouver','Manager');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(5,'Robert', 'Black', '19840115', '19980808', 2334.78, 'Vancouver','Tester');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(6,'Linda', 'Green', '19870730', '19960104', 4322.78,'New York', 'Tester');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(7,'David', 'Larry', '19901231', '19980212', 7897.78,'New York', 'Manager');

Query OK, 1 row affected (0.02 sec)

mysql>

mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

-> values(8,'James', 'Cat', '19960917', '20020415', 1232.78,'Vancouver', 'Tester');

Query OK, 1 row affected (0.00 sec)

mysql>

mysql> select * from Employee;

+------+------------+-----------+------------+------------+---------+-----------+-------------+

| id | first_name | last_name | start_date | end_date | salary | city | description |

+------+------------+-----------+------------+------------+---------+-----------+-------------+

| 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer |

| 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester |

| 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester |

| 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager |

| 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester |

| 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester |

| 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager |

| 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester |

+------+------------+-----------+------------+------------+---------+-----------+-------------+

8 rows in set (0.00 sec)

mysql> DELIMITER //

mysql>

mysql> CREATE TRIGGER myTrigger BEFORE UPDATE ON employee //创建mysql触发器

-> FOR EACH ROW

-> BEGIN

->

-> IF NEW.id > 5 THEN

-> SET NEW.first_name = NEW.first_name+ " *";

-> END IF;

->

-> IF NEW.salary IS NULL OR NEW.salary = 0 THEN

-> SET NEW.salary = 100;

-> ELSE

-> SET NEW.salary = NEW.salary + 100;

-> END IF;

->

-> END

->

-> //

Query OK, 0 rows affected (0.02 sec)

mysql> DELIMITER ;

mysql>

mysql> SELECT * FROM INFORMATION_SCHEMA.TRIGGERS;

+-----------------+----------------+--------------+--------------------+----------------------+---------------------+--------------------+-------------

-+------------------+----------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------+--------------------+---------------+---------------------------

-+----------------------------+--------------------------+--------------------------+---------+----------+----------------+

| TRIGGER_CATALOG | TRIGGER_SCHEMA | TRIGGER_NAME | EVENT_MANIPULATION | EVENT_OBJECT_CATALOG | EVENT_OBJECT_SCHEMA | EVENT_OBJECT_TABLE | ACTION_ORDER

| ACTION_CONDITION | ACTION_STATEMENT

| ACTION_ORIENTATION | ACTION_TIMING | ACTION_REFERENCE_OLD_TABLE

| ACTION_REFERENCE_NEW_TABLE | ACTION_REFERENCE_OLD_ROW | ACTION_REFERENCE_NEW_ROW | CREATED | SQL_MODE | DEFINER |

+-----------------+----------------+--------------+--------------------+----------------------+---------------------+--------------------+-------------

-+------------------+----------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------+--------------------+---------------+---------------------------

-+----------------------------+--------------------------+--------------------------+---------+----------+----------------+

| NULL | test | myTrigger | UPDATE | NULL | test | employee | 0

| NULL | BEGIN

IF NEW.id > 5 THEN

SET NEW.first_name = NEW.first_name+ " *";

END IF;

IF NEW.salary IS NULL OR NEW.salary = 0 THEN

SET NEW.salary = 100;

ELSE

SET NEW.salary = NEW.salary + 100;

END IF;

END | ROW | BEFORE | NULL | NULL | OLD | NEW

| NULL | | root@localhost |

+-----------------+----------------+--------------+--------------------+----------------------+---------------------+--------------------+-------------

-+------------------+----------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------+--------------------+---------------+---------------------------

-+----------------------------+--------------------------+--------------------------+---------+----------+----------------+

1 row in set (0.03 sec)

mysql> DROP TRIGGER myTrigger; //删除mysql触发器

Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM INFORMATION_SCHEMA.TRIGGERS; //查询触发器系统表，确认触发器是否删除

Empty set (0.02 sec)

mysql> drop table Employee;

Query OK, 0 rows affected (0.00 sec)

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