create table userinfo(
id int primary key auto_increment,
name varchar(100) not null,
age char(3) check('男' or '女'),
time_info timestamp default current_timestamp
);
insert into userinfo(name,age) values('zzg','男'),('fz','女');
insert into userinfo(name,age) values('zzg1','男'),('fz1','女'),('fz2','女'),('fz3','女');
insert into userinfo(name,age) values('zzg1','男'),('fz4','女'),('fz5','女'),('fz6','女');
insert into userinfo(name,age) values('zzg1','男'),('fz7','女'),('fz8','女'),('fz9','女');
insert into userinfo(name,age) values('zzg1','男'),('fz10','女'),('fz11','女'),('fz12','女');
insert into userinfo(name,age) values('zzg1','男'),('fz13','女'),('fz14','女'),('fz15','女');
insert into userinfo(name,age) values('zzg1','男'),('fz16','女'),('fz17','女'),('fz19','女');
id int primary key auto_increment,
name varchar(100) not null,
age char(3) check('男' or '女'),
time_info timestamp default current_timestamp
);
insert into userinfo(name,age) values('zzg','男'),('fz','女');
insert into userinfo(name,age) values('zzg1','男'),('fz1','女'),('fz2','女'),('fz3','女');
insert into userinfo(name,age) values('zzg1','男'),('fz4','女'),('fz5','女'),('fz6','女');
insert into userinfo(name,age) values('zzg1','男'),('fz7','女'),('fz8','女'),('fz9','女');
insert into userinfo(name,age) values('zzg1','男'),('fz10','女'),('fz11','女'),('fz12','女');
insert into userinfo(name,age) values('zzg1','男'),('fz13','女'),('fz14','女'),('fz15','女');
insert into userinfo(name,age) values('zzg1','男'),('fz16','女'),('fz17','女'),('fz19','女');