燕十八老师mysql高级篇代码（手敲）
这里要首先尊重和感谢一下燕十八老师的辛苦录制的视频：非常非常谢谢无私的备课和讲课
本着公益分享和支持原创的态度；
如果他本人觉得有不妥的地方，请联系我，我会删掉。
听说他自己也有php高性能架构班的课程视频。。。额，这个是培训课程，不免费。。。
可否也公开供大家学习一下，或者谁有能发给我，学习观摩一下？
delimiter $
create table goods(
gid int,
name varchar(20),
num smallint
);
create table ord(
oid int,
gid int,
much smallint
);
insert into goods values
(1,'cat',34),
(2,'dog',65),
(3,'pig',21);
1）触发器：
create trigger t1
after
insert
on ord
for each row
begin
update goods set num=num-2 where gid=1;
end$
show triggers \G
create trigger t2
after
insert
on ord
for each row
begin
update goods set num=num-new.much where gid=new.gid;
end$
create trigger t3
after
delete
on ord
for each row
begin
update goods set num=num+old.much where gid=old.gid;
end$
create trigger t4
before
update
on ord
for each row
begin
update goods set num=num+old.much-new.much where gid=new.gid;
end$
create trigger t5(错误的例子)
after
insert
on ord
for each row
begin
declare rnum int;
select num into rnum from goods where gid=new.gid;
if new.much >rnum then
set new.much = rnum;
end if;
update goods set num=num-new.much where gid=new.gid;
end$
create trigger t5(错误的例子)
before #这里改了
insert
on ord
for each row
begin
declare rnum int;
select num into rnum from goods where gid=new.gid;
if new.much >rnum then
set new.much = rnum;
end if;
update goods set num=num-new.much where gid=new.gid;
end$
for each row 说明 Mysql 只有行级触发器，oracle里除了行级触发器还有语句级触发器。
2）存储过程：
create procedure p1()
begin
select 'hello' from dual;
end$
call p1()$
create procedure p2()
begin
declare age int default 18;
declare height int default 180;
select concat('年龄是',age,'身高是',height);
end$
create procedure p3()
begin
declare age int default 18;
set age:= age+20;
select concat('20年后年龄是',age);
end$
create procedure p4()
begin
declare age int default 18;
if age >=18 then
select '成年';
else
select '未成年';
end if;
end$
create procedure p5(width int ,height int)
begin
select concat('你的面积是', width * height ) as area;
if width >height then
select '你挺胖';;
elseif width < height then
select ‘你挺瘦’;
else
select '你挺方';
endif;
end$
create procedure p6()
begin
declare total int default 0;
declare num int default 0;
while num <100 do
set num:=num+1;
set total:= total +num;
end while;
select total;
end$
create procedure p7(in n int)
begin
declare total int default 0;
declare num int default 0;
while num set num:=num+1; set total:= total +num; end while; select total; end$ create procedure p8(in n int ,out total int) begin declare num int default 0; set total :=0; #null 碰到任何操作都会变成null while num set num:=num+1; set total :=total+num; end while; end$ call p8(100,@summary)$ select @summary create procedure p9(inout age int) begin set age:=age +20; end$ set @currage =18$ call p9(@currage)$ select @currage$ create procedure p10() begin declare pos int default 0; set pos := floor(5*rand()); case pos when 1 then select 'still flying'; when 2 then select 'fall in sea'; when 3 then select 'in the island'; else select 'I don't know'; end case; end$ create procedure p11() begin declare total int default 0; declare i int default 0; repeat set i:=i+1; set total :=total +i; until i>=100 end repeat; select total; end$ create procedure p12() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare getgoods cursor for select gid, num , name from goods; open getgoods; fetch getgoods into row_gid,row_num,row_name; select row_num,row_name; close getgoods; end$ create procedure p13() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare getgoods cursor for select gid, num , name from goods; open getgoods; fetch getgoods into row_gid,row_num,row_name; #cat select row_num,row_name; fetch getgoods into row_gid,row_num,row_name;#dog select row_num,row_name; fetch getgoods into row_gid,row_num,row_name;#pig select row_num,row_name; fetch getgoods into row_gid,row_num,row_name;#error select row_num,row_name; close getgoods; end$ #逻辑处理游标越界 create procedure p14() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare cnt int default 0; declare i int default 0; declare getgoods cursor for select gid, num , name from goods; select count(*) into cnt from goods; open getgoods; repeat set fetch getgoods into row_gid,row_num,row_name; #cat select row_num,row_name; until i >= cnt end repeat; close getgoods; end$ create procedure p15() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare you int default 1; declare getgoods cursor for select gid, num , name from goods; select count(*) into cnt from goods; declare continue handler for NOT FOUND set you :=0; open getgoods; repeat set fetch getgoods into row_gid,row_num,row_name; select row_num,row_name; until you=0 end repeat; close getgoods; end$ show warnings$ create procedure p16() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare you int default 1; declare getgoods cursor for select gid, num , name from goods; select count(*) into cnt from goods; declare exit handler for NOT FOUND set you :=0;#这里的handler类型改成了exit open getgoods; repeat set fetch getgoods into row_gid,row_num,row_name; select row_num,row_name; until you=0 end repeat; close getgoods; end$ #还有一种undo handler 目前mysql 还不支持。。。表示前面的语句撤销 #接下来的存储过程才应该是游标的正确使用方式： #一定要用continue handler ，通过逻辑来控制。 create procedure p17() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare you int default 1; declare getgoods cursor for select gid, num , name from goods; select count(*) into cnt from goods; declare continue handler for NOT FOUND set you :=0; open getgoods; fetch getgoods into row_gid,row_num,row_name; repeat set select row_num,row_name; fetch getgoods into row_gid,row_num,row_name; until you=0 end repeat; close getgoods; end$ #换成while 循环 create procedure p18() begin declare row_gid int; declare row_num int; declare row_name varchar(20); declare you int default 1; declare getgoods cursor for select gid, num , name from goods; select count(*) into cnt from goods; declare continue handler for NOT FOUND set you :=0; open getgoods; fetch getgoods into row_gid,row_num,row_name; while you =1 do select row_num,row_name; fetch getgoods into row_gid,row_num,row_name; end while; close getgoods; end$ 3)权限 use mysql$ desc user$ select host,user,password from user$ 命令行：mysql -hXXXXXXXXXXXXX -uroot -p 重刷权限 ：flush privileges$ 修改密码：update user set password=password('111111') where xxxx; select datebase()$ show tables;#db 表和 tables_priv表很重要 select host,user,password from user$ grant all on *.* to lisi@'192.168.1.%' identified by '1111111'$ select * from user where user='lisi' \G revoke all on *.* from lisi@'192.168.1.%'$ flush privileges$ grant all on ecshop.* to lisi@'192.168.1.%' $ revoke all on ecshop.* from lisi@'192.168.1.%'$ grant insert update,select on gy3.goods to lisi@'192.168.1.%'$ 4)主从复制； vim /etc/my.cnf server-id=201 log-bin=mysql-bin #二进制日志的格式有mixed、row、statement #statement 记录的是执行语句 #row 记录的是磁盘变化 binlog-format=mixed #把旧的日志删除 cd /var/lib/mysql #另一台 vim /etc/my.cnf server-id=202 log-bin=mysql-bin binlog-format =mixed relay-log=mysql-relay #启动： service mysqld start #不出问题就不要执行下面两条，如果执行请一条一条执行 #mysqld_safe --user=mysql & #ps aux|grep mysql #ls /var/lib/mysql/mysql.sock #mysql -uroot -p -S /var/lib/mysql/myssql.sock #ln -s /var/lib/mysql/mysql.sock /tem/mysqld.sock show master status; show slave status; #主服务器授权 grant replication client,replication slave on *.* to repl@'192.168.1.%' identified by 'repl'; flush privileges; #从服务器 change master to master_host='192.168.1.201', master_user='repl', master_password='repl', master_log_file='mysql-bin.00001' master_log_pos=348;#这个根据刚刚show master status 的结果来定 #启动服务 start slave; #出错，last_io_error telnet ip 3306 不通 ping ip 通 说明是防火墙的问题 关掉防火墙 service iptables stop; stop slave; start slave; #同步过程怎么避免冲突 set global auto_increment_increment=2; set global auto_increment_offset=1; set session auto_increment_increment=2; set session auto_increment_offset=1; #另一台 set global auto_increment_increment=2; set global auto_increment_offset=2; set session auto_increment_increment=2; set session auto_increment_offset=2; #把auto_increment_increment 和 auto-increment-offset 写到对应的配置文件中，避免下次重启后失效