构建一个大表(400 万)

#创建表DEPT
CREATE TABLE dept( /*部门表*/
deptno MEDIUMINT   UNSIGNED  NOT NULL  DEFAULT 0, 
dname VARCHAR(20)  NOT NULL  DEFAULT "",
loc VARCHAR(13) NOT NULL DEFAULT ""
) ENGINE=MyISAM DEFAULT CHARSET=utf8 ;



#创建表EMP雇员
CREATE TABLE emp
(empno  MEDIUMINT UNSIGNED  NOT NULL  DEFAULT 0, /*编号*/
ename VARCHAR(20) NOT NULL DEFAULT "", /*名字*/
job VARCHAR(9) NOT NULL DEFAULT "",/*工作*/
mgr MEDIUMINT UNSIGNED NOT NULL DEFAULT 0,/*上级编号*/
hiredate DATE NOT NULL,/*入职时间*/
sal DECIMAL(7,2)  NOT NULL,/*薪水*/
comm DECIMAL(7,2) NOT NULL,/*红利*/
deptno MEDIUMINT UNSIGNED NOT NULL DEFAULT 0 /*部门编号*/
)ENGINE=MyISAM DEFAULT CHARSET=utf8 ;

#工资级别表
CREATE TABLE salgrade
(
grade MEDIUMINT UNSIGNED NOT NULL DEFAULT 0,
losal DECIMAL(17,2)  NOT NULL,
hisal DECIMAL(17,2)  NOT NULL
)ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO salgrade VALUES (1,700,1200);
INSERT INTO salgrade VALUES (2,1201,1400);
INSERT INTO salgrade VALUES (3,1401,2000);
INSERT INTO salgrade VALUES (4,2001,3000);
INSERT INTO salgrade VALUES (5,3001,9999);

# 随机产生字符串
#定义一个新的命令结束符合
delimiter $$
#删除自定的函数
drop  function rand_string $$

#这里我创建了一个函数. 

#rand_string(n INT) rand_string 是函数名 (n INT) //该函数接收一个整数
create function rand_string(n INT) 
returns varchar(255) #该函数会返回一个字符串
begin 
#chars_str定义一个变量 chars_str,类型是 varchar(100),默认值'abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ';
 declare chars_str varchar(100) default
   'abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ';
 declare return_str varchar(255) default '';
 declare i int default 0;
 while i < n do 
   set return_str =concat(return_str,substring(chars_str,floor(1+rand()*52),1));
   set i = i + 1;
   end while;
  return return_str;
  end $$


delimiter ;
select rand_string(6);

# 随机产生部门编号
delimiter $$
drop  function rand_num $$

#这里我们又自定了一个函数
create function rand_num( )
returns int(5)
begin 
 declare i int default 0;
 set i = floor(10+rand()*500);
return i;
  end $$


delimiter ;
select rand_num();

#******************************************
#向emp表中插入记录(海量的数据)


delimiter $$
drop procedure insert_emp $$


#随即添加雇员[光标]  400w
create procedure insert_emp(in start int(10),in max_num int(10))
begin
declare i int default 0; 
#set autocommit =0 把autocommit设置成0
 set autocommit = 0;  
 repeat
 set i = i + 1;
 insert into emp values ((start+i) ,rand_string(6),'SALESMAN',0001,curdate(),2000,400,rand_num());
  until i = max_num
 end repeat;
   commit;
 end $$


delimiter ;
#调用刚刚写好的函数, 1800000条记录,从100001号开始
call insert_emp(100001,4000000);


#**************************************************************
#  向dept表中插入记录

delimiter $$
drop procedure insert_dept $$


create procedure insert_dept(in start int(10),in max_num int(10))
begin
declare i int default 0; 
 set autocommit = 0;  
 repeat
 set i = i + 1;
 insert into dept values ((start+i) ,rand_string(10),rand_string(8));
  until i = max_num
 end repeat;
   commit;
 end $$


delimiter ;
call insert_dept(100,10);





#------------------------------------------------
#向salgrade 表插入数据
delimiter $$
drop procedure insert_salgrade $$
create procedure insert_salgrade(in start int(10),in max_num int(10))
begin
declare i int default 0; 
 set autocommit = 0;
 ALTER TABLE emp DISABLE KEYS;  
 repeat
 set i = i + 1;
 insert into salgrade values ((start+i) ,(start+i),(start+i));
  until i = max_num
 end repeat;
   commit;
 end $$
delimiter ;
#测试不需要了
#call insert_salgrade(10000,1000000);





#----------------------------------------------