MySql视图和存储程序

create view(字段别名...) as 选择语句
例:
create view(ln,fn) as select last_name,first_name from student;

delimiter 分隔符名
create procedure 函数名()
begin
函数体
end;
delimiter #结束分隔符
call 函数名

例:
delemiter $
create procedure show_times()
begin
   select CURRENT_TIMESTAMP as ‘Local Time‘;
   select UTC_TIMESTAMP as ‘UTC Time‘;
end$
delemiter
call show_times(); #调用

create function 函数名(参数列表)
returns type
stmt
create procedure 存储过程名(参数列表)
stmt

delemiter $
create function test(emp_salary INT)
returns INT
READS SQL DATA
BEGIN
 RETURN(select count(*) from emp where salary > 5000 and salary=emp_salary);
END$
delemiter;

delemiter $
CREATE PROCEDURE show_born_in_year(p_year INT)
BEGIN
    SELECT first_name,last_name,birth,death
    from president
    where YEAR(birth)=p_year
END$
delemiter;

create trigger trigger_name     #触发器名
[before|after]                  #触发时机
[insert|delete|update]          #激活触发器的语句
ON table_name                   #关联表
FOR EACH ROW trigger_stmt       #内容

create table t(percent INT, dt DATETIME);
delimiter $
create trigger bi_t BEFORE INSERT ON t
      FOR EACH ROW BEGIN
           IF NEW.percent < 0 then
                 SET NEW.percent=0;
           ELSEIF NEW.percent > 100 then
                 SET NEW.percent=100;
           END IF;
end$  NEW.dt=CURRENT_TIMESTAMP;
end$
delimiter;