ORACLE建立主鍵自增表

--建立表，設定主鍵自增
Create Table stu(
uerId NUMBER(4) Not Null Primary Key,
username Varchar(20),
userpass Varchar(20),
email varchar2(30),
grade NUMBER(5)
);
Commit;
--小查一下
Select * From STU;
--建立主鍵自增序列
Create Sequence emp_sequence
Increment By 1
Start With 1
Nomaxvalue
Nocycle
Nocache;
Commit;
--建立觸發器
Create Trigger "trigger_on_STU" Before
Insert On STU For Each Row When (New.uerId Is Null)
Begin
Select emp_sequence.Nextval Into :New.uerId From dual;
End;
--插入資料
Insert Into STU(username,userpass,email,grade) Values('admin','admin','admin@admin.com',1);
Insert Into STU(username,userpass,email,grade)  Values('dhy','dhy','dhy@admin.com',1);
Insert Into STU(username,userpass,email,grade)  Values('nsr','nsr','nsr@admin.com',1);
Insert Into STU(username,userpass,email,grade)  Values('adamin','addmin','admdin@admin.com',5);
Insert Into STU(username,userpass,email,grade)  Values('dhay','dhay','dhay@admin.com',3);
Insert Into STU(username,userpass,email,grade)  Values('ansr','ansr','ansr@admin.com',4);
Commit;
--查看資料
Select * From STU;