select constraint_name from user_constraints where table_name='USERINFO_P1';
select constraint_name from user_constraints where table_name='USERINFO_P';
select constraint_name from user_constraints where table_name='USERINFO_P';
2018-01-08
create table userinfo_p1(id number(6,0),username varchar2(20),userpwd varchar2(20),constraint pk_id_username primary key(id,username));
desc userinfo_p1
desc user_constraint
desc userinfo_p1
desc user_constraint
2018-01-08
create table userinfo_p(id number(6,0) primary key,username varchar2(20),userpwd varchar2(20));
desc userinfo_p
desc userinfo_p
2018-01-08
alter table userinfo modify username varchar2(20) not null;
delete fromuserinfo;
later table userinfo modify username varchar2(20) not null;
desc userinfo;
later table userinfo modify username varchar(20) null;
desc userinfo;
delete fromuserinfo;
later table userinfo modify username varchar2(20) not null;
desc userinfo;
later table userinfo modify username varchar(20) null;
desc userinfo;
2018-01-08
create table userinfo_1(id number(6,0), username varchar2(20) not null,userpwd varchar2(20) not null);
desc userinfo_1
insert into userinfo_1(id) values(1);
desc userinfo_1
insert into userinfo_1(id) values(1);
2018-01-08
create table testdel as select * from userinfo;
delete from testdel;
select * from testdel;
select username from userinfo;
delete from userinfo where username='yyy';
select username from userinfo;
delete from testdel;
select * from testdel;
select username from userinfo;
delete from userinfo where username='yyy';
select username from userinfo;
2018-01-08
update userinfo set userpwd='111111';
select userpwd from userinfo;
update userinfo set userpwd='111',email='111@126.com';
select userpwd,email from userinfo;
select username from userinfo;
update userinfo set userpwd='123456' where username='xxx';
select username,userpwd from userinfo;
select userpwd from userinfo;
update userinfo set userpwd='111',email='111@126.com';
select userpwd,email from userinfo;
select username from userinfo;
update userinfo set userpwd='123456' where username='xxx';
select username,userpwd from userinfo;
2018-01-08
insert into userinfo_new select * from userinfo;
select id from useinfo_new;
insert into userinfo)new(id,username) select id,username from userinfo;
select id,username from userinfo_new;
select id from useinfo_new;
insert into userinfo)new(id,username) select id,username from userinfo;
select id,username from userinfo_new;
2018-01-08
create table userinfo_new as select * from userinfo;
desc userinfo_new;
select * from useinfo_new;
create table userinfo_new1 as select id,username from userinfo;
select * from userinfo_new1;
desc userinfo_new;
select * from useinfo_new;
create table userinfo_new1 as select id,username from userinfo;
select * from userinfo_new1;
2018-01-08
create table userinfo1(id number(6,0),regdate date default sysdate);
insert into userinfo1(id) values(1);
select *from userinfo1;
alter table userinfo modefy email deault '无';
insert into userinfo(id) values(3);
select id,email from userinfo;
insert into userinfo(id,email) values（4,'aaa');
insert into userinfo1(id) values(1);
select *from userinfo1;
alter table userinfo modefy email deault '无';
insert into userinfo(id) values(3);
select id,email from userinfo;
insert into userinfo(id,email) values（4,'aaa');
2018-01-08
insert into userinfo values(1,'xxx','123','xxx@126.com',sysdate);
select * from userinfo;
insert into userinfo(id,username,userpwd) values(2,'yyy','123');
select username,userpwd from userinfo;
select * from userinfo;
insert into userinfo(id,username,userpwd) values(2,'yyy','123');
select username,userpwd from userinfo;
2018-01-08
truncate table new_userinfo;
desc new_userinfo
drop table new_userinfo;
desc new_userinfo
desc new_userinfo
drop table new_userinfo;
desc new_userinfo
2018-01-06
alter table userinfo rename column email to new_email;
desc userinfo
rename userinfo to new_userinfo;
desc userinfo
desc new_userinfo
desc userinfo
rename userinfo to new_userinfo;
desc userinfo
desc new_userinfo
2018-01-06
alter table userinfo add remarks varchar2(500);
desc userinfo
alter table userinfo modify remarks varchar2(400);
desc userinfo
alter table userinfo modify userpwd number(6,0);
desc userinfo
alter table userinfo drop column remarks;
desc userinfo
desc userinfo
alter table userinfo modify remarks varchar2(400);
desc userinfo
alter table userinfo modify userpwd number(6,0);
desc userinfo
alter table userinfo drop column remarks;
desc userinfo
2018-01-06