1.create or replace view emp_view as select * fromt4 ;给t4表创建一个名为emp_view的视图2.drop viewemp_view 删除视图=======================================
1.创建一个存储过程(查询所有数据)create procedurep1 ()
READS SQL DATABEGIN
select * fromt4;END
2.创建一个存储过程(查询传参数据)create procedure p2(IN tid INT)
READS SQL DATABEGIN
select * from t4 where id =tid;END
3.创建一个存储过程(查询传参数据并返回name)create procedure p3(IN tid INT,OUT tname CHAR(255))
READS SQL DATABEGIN
select name from t4 where id = tid intotname;END
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1.创建一个存储函数(函数必须有返回值)create function p4(IN tid INT)RETURNS CHAR(255)
DETERMINISTIC
READS SQL DATABEGIN
DECLARE t_name CHAR(255);SELECT tname from t4 where id = tid intot_name;RETURNt_name;END
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1.定义错误条件和处理
情景1:比如过程中要插入的数据唯一键值已存在create procedurep5 ()BEGIN
DECLARE CONTINUE HANDLER FOR SQLSTATE ‘23000‘ set @x2 = 1; //23000在mysql中代表建已存在或重复的错误代码set @x = 1;insert into ...... //假设这条不重复set @x = 2;insert into ...... //假设这条不重复set @x = 3;insert into ..... //重复END调用:
call p5();select @x,@x2;
将输出:3,1原因:前面2条都顺利执行,@x = 3,最后一条重复,也就是将@x2设置成了1;=============================================
1.光标概念(实际上就是fetch结果集用的)create procedurep6()
READS SQL DATA//表示过程只包含读不包含写BEGIN
DECLARE tid int;//定义idDECLARE tname char;//定义nameDECLARE tcur cursor for select id,name from t4;//定义光标DECLARE exit handler for not found tcur;//如果光标为空则退出,不允许继续执行set @error = ‘‘;//设置返回调用erroropentcur;
repeatfetch tcur intotid,tname;if tid = 1 then
set @error = ‘我是1,但是我报错了‘;else
set @error = ‘我不是1啊,真的啊!‘;end if;
until0 endrepeat;close tcur;//关闭END;===============================================
1.流程控制if:if 1=1 then我是1;else我不是1;end if
case:case
when 1=1 then我是1;else我不是1;end caseloop:
emp: LOOP
#...code.....ENDLOOP emp;
leave emp;//表示从标注的流程中退出(emp表示上面loop的标注) 相当于php中break,只不过leave要指定需要被跳出的结构体
iterate emp;//表示此次循环跳过余下的代码块 相当于php中的continue
repeat:
repeat//循环开始相当于php的do...while...(因为他是在循环结束的时候做判断,因此此循环体至少会被执行一次)
#....code....//相关内容
until1=2 end repeat //如果条件为假则退出循环while://跟php中的while一个概念,只是语法区别while 1=1 do //很明显,这是个死循环
#...code.....end while;================================================
1.时间触发器(时间调度器)1.默认时间触发器是关闭状态set GLOBAL event_scheduler = 1开启2.show variables like ‘scheduler‘ 查看时间调度器开启/关闭状态3.show events;//查看所有调度器4.alter event emp disable; //禁用名为emp的调度器5.drop event emp; //删除名为emp的调度器6.创建一个调度器create event emp //调度器名次on schedule every 5 second //时间5秒
do//开始insert into haha values (NULL); //执行体=================================================PS::-07-08继续学习ing.....