版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_18377515/article/details/82313428
本文讨论的是存储程序和视图，存储程序包括：存储过程和函数、触发器、事件。
mysql的各种语法：https://dev.mysql.com/doc/refman/5.7/en/sql-syntax.html
存储过程和函数
语法
存储过程的body 是以BEGIN开头，END结尾的代码块，里面包含set、repeat loop语句
语法：
创建存储过程和函数
CREATE
[DEFINER = { user | CURRENT_USER }]
PROCEDURE sp_name ([proc_parameter[,...]])
[characteristic ...] routine_body
CREATE
[DEFINER = { user | CURRENT_USER }]
FUNCTION sp_name ([func_parameter[,...]])
RETURNS type
[characteristic ...] routine_body
proc_parameter:
[ IN | OUT | INOUT ] param_name type
func_parameter:
param_name type
type:
Any valid MySQL data type
characteristic:
COMMENT 'string'
| LANGUAGE SQL
| [NOT] DETERMINISTIC
| { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
| SQL SECURITY { DEFINER | INVOKER }
routine_body:
Valid SQL routine statement
删除存储过程和函数
DROP {PROCEDURE | FUNCTION} [IF EXISTS] sp_name
修改存储过程和函数
ALTER PROCEDURE proc_name [characteristic ...]
characteristic:
COMMENT 'string'
| LANGUAGE SQL
| { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
| SQL SECURITY { DEFINER | INVOKER }
查看存储过程和函数的定义
SHOW CREATE {PROCEDURE|FUNCTION} sp_name
查看存储过程和函数的状态
SHOW {PROCEDURE|FUNCTION} STATUS
[LIKE 'pattern' | WHERE expr]例子
procedure例子：
delimiter //
CREATE PROCEDURE dorepeat(p1 INT)
BEGIN
SET @x = 0;
REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT;
END;//
call dorepeat(1000);
select @x;
functions 例子
CREATE FUNCTION hello (s CHAR(20))
RETURNS CHAR(50) DETERMINISTIC
RETURN CONCAT('Hello, ',s,'!');
select hello('world');
查看dorepeat存储过程的定义
SHOW CREATE PROCEDURE dorepeat;
触发器
语法
创建触发器
CREATE
[DEFINER = { user | CURRENT_USER }]
TRIGGER trigger_name
trigger_time trigger_event
ON tbl_name FOR EACH ROW
[trigger_order]
trigger_body
trigger_time: { BEFORE | AFTER }
trigger_event: { INSERT | UPDATE | DELETE }
trigger_order: { FOLLOWS | PRECEDES } other_trigger_name删除触发器DROP TRIGGER [IF EXISTS] [schema_name.]trigger_name
例子
例子1：
CREATE TABLE account (acct_num INT, amount DECIMAL(10,2));
CREATE TRIGGER ins_sum BEFORE INSERT ON account
FOR EACH ROW SET @sum = @sum + NEW.amount;
由这个图可以看出触发器是针对某张表的。
触发器调用结果
SET @sum = 0;
INSERT INTO account VALUES(137,14.98),(141,1937.50),(97,-100.00);
SELECT @sum AS 'Total amount inserted';
例子2：
CREATE TABLE test1(a1 INT);
CREATE TABLE test2(a2 INT);
CREATE TABLE test3(a3 INT NOT NULL AUTO_INCREMENT PRIMARY KEY);
CREATE TABLE test4(
a4 INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
b4 INT DEFAULT 0
);
delimiter |
CREATE TRIGGER testref BEFORE INSERT ON test1
FOR EACH ROW
BEGIN
INSERT INTO test2 SET a2 = NEW.a1;
DELETE FROM test3 WHERE a3 = NEW.a1;
UPDATE test4 SET b4 = b4 + 1 WHERE a4 = NEW.a1;
END;
|
delimiter ;
INSERT INTO test3 (a3) VALUES
(NULL), (NULL), (NULL), (NULL), (NULL),
(NULL), (NULL), (NULL), (NULL), (NULL);
INSERT INTO test4 (a4) VALUES
(0), (0), (0), (0), (0), (0), (0), (0), (0), (0);
INSERT INTO test1 VALUES
(1), (3), (1), (7), (1), (8), (4), (4);结果：
mysql> SELECT * FROM test1;
+------+
| a1 |
+------+
| 1 |
| 3 |
| 1 |
| 7 |
| 1 |
| 8 |
| 4 |
| 4 |
+------+
8 rows in set (0.00 sec)
mysql> SELECT * FROM test2;
+------+
| a2 |
+------+
| 1 |
| 3 |
| 1 |
| 7 |
| 1 |
| 8 |
| 4 |
| 4 |
+------+
8 rows in set (0.00 sec)
mysql> SELECT * FROM test3;
+----+
| a3 |
+----+
| 2 |
| 5 |
| 6 |
| 9 |
| 10 |
+----+
5 rows in set (0.00 sec)
mysql> SELECT * FROM test4;
+----+------+
| a4 | b4 |
+----+------+
| 1 | 3 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 1 |
| 9 | 0 |
| 10 | 0 |
+----+------+
10 rows in set (0.00 sec)查看触发器
SHOW CREATE TRIGGER testref;
事件
语法
创建事件
CREATE
[DEFINER = { user | CURRENT_USER }]
EVENT
[IF NOT EXISTS]
event_name
ON SCHEDULE schedule
[ON COMPLETION [NOT] PRESERVE]
[ENABLE | DISABLE | DISABLE ON SLAVE]
[COMMENT 'string']
DO event_body;
schedule:
AT timestamp [+ INTERVAL interval] ...
| EVERY interval
[STARTS timestamp [+ INTERVAL interval] ...]
[ENDS timestamp [+ INTERVAL interval] ...]
interval:
quantity {YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE |
WEEK | SECOND | YEAR_MONTH | DAY_HOUR | DAY_MINUTE |
DAY_SECOND | HOUR_MINUTE | HOUR_SECOND | MINUTE_SECOND}修改事件
ALTER
[DEFINER = { user | CURRENT_USER }]
EVENT event_name
[ON SCHEDULE schedule]
[ON COMPLETION [NOT] PRESERVE]
[RENAME TO new_event_name]
[ENABLE | DISABLE | DISABLE ON SLAVE]
[COMMENT 'string']
[DO event_body]例子
DEMO1：创建事件
SELECT NOW();
CREATE EVENT e_totals
ON SCHEDULE AT '2018-09-02 16:04:19'
DO INSERT INTO test.test1 VALUES (20);DEMO2：修改事件
CREATE EVENT myevent
ON SCHEDULE
EVERY 6 HOUR
COMMENT 'A sample comment.'
DO
UPDATE myschema.mytable SET mycol = mycol + 1;
ALTER EVENT myevent
ON SCHEDULE
EVERY 12 HOUR
STARTS CURRENT_TIMESTAMP + INTERVAL 4 HOUR;视图
语法
创建视图
CREATE
[OR REPLACE]
[ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}]
[DEFINER = { user | CURRENT_USER }]
[SQL SECURITY { DEFINER | INVOKER }]
VIEW view_name [(column_list)]
AS select_statement
[WITH [CASCADED | LOCAL] CHECK OPTION]修改视图
ALTER
[ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}]
[DEFINER = { user | CURRENT_USER }]
[SQL SECURITY { DEFINER | INVOKER }]
VIEW view_name [(column_list)]
AS select_statement
[WITH [CASCADED | LOCAL] CHECK OPTION]删除视图
DROP VIEW [IF EXISTS]
view_name [, view_name] ...
[RESTRICT | CASCADE]例子
CREATE TABLE t (qty INT, price INT);
INSERT INTO t VALUES(3, 50), (5, 60);
CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t;
SELECT * FROM v;
+------+-------+-------+
| qty | price | value |
+------+-------+-------+
| 3 | 50 | 150 |
| 5 | 60 | 300 |
+------+-------+-------+
SELECT * FROM v WHERE qty = 5;
+------+-------+-------+
| qty | price | value |
+------+-------+-------+
| 5 | 60 | 300 |
+------+-------+-------+