oracel Alter table 给表增加主键 primary key

oracel alter table 给表增加主键 primary key

sql>
sql> create table emp (empno number(4) not null,
2                    ename varchar2(10),
3                    job varchar2(9),
4                    mgr number(4),
5                    hiredate date,
6                    sal number(7, 2),
7                    comm number(7, 2),
8                    deptno number(2));

table created.

sql>
sql> insert into emp values (7369, 'smith', 'clerk',    7902, to_date('17-dec-1980', 'dd-mon-yyyy'), 800, null, 20);

1 row created.

sql> insert into emp values (7499, 'allen', 'salesman', 7698, to_date('20-feb-1981', 'dd-mon-yyyy'), 1600, 300, 30);

1 row created.

sql> insert into emp values (7521, 'ward', 'salesman', 7698, to_date('22-feb-1981', 'dd-mon-yyyy'), 1250, 500, 30);

1 row created.

sql> insert into emp values (7566, 'jones', 'manager', 7839, to_date('2-apr-1981', 'dd-mon-yyyy'), 2975, null, 20);

1 row created.

sql> insert into emp values (7654, 'martin', 'salesman', 7698,to_date('28-sep-1981', 'dd-mon-yyyy'), 1250, 1400, 30);

1 row created.

sql> insert into emp values (7698, 'blake', 'manager', 7839,to_date('1-may-1981', 'dd-mon-yyyy'), 2850, null, 30);

1 row created.

sql> insert into emp values (7782, 'clark', 'manager', 7839,to_date('9-jun-1981', 'dd-mon-yyyy'), 2450, null, 10);

1 row created.

sql> insert into emp values (7788, 'scott', '易做图yst', 7566,to_date('09-dec-1982', 'dd-mon-yyyy'), 3000, null, 20);

1 row created.

sql> insert into emp values (7839, 'king', 'president', null,to_date('17-nov-1981', 'dd-mon-yyyy'), 5000, null, 10);

1 row created.

sql> insert into emp values (7844, 'turner', 'salesman', 7698,to_date('8-sep-1981', 'dd-mon-yyyy'), 1500, 0, 30);

1 row created.

sql> insert into emp values (7876, 'adams', 'clerk', 7788,to_date('12-jan-1983', 'dd-mon-yyyy'), 1100, null, 20);

1 row created.

sql> insert into emp values (7900, 'james', 'clerk', 7698,to_date('3-dec-1981', 'dd-mon-yyyy'), 950, null, 30);

1 row created.

sql> insert into emp values (7902, 'ford', '易做图yst', 7566,to_date('3-dec-1981', 'dd-mon-yyyy'), 3000, null, 20);

1 row created.

sql> insert into emp values (7934, 'miller', 'clerk', 7782,to_date('23-jan-1982', 'dd-mon-yyyy'), 1300, null, 10);

1 row created.

sql>
sql>
sql> create table emp_reg
2 as
3 select * from emp;

sql>
sql> alter table emp_reg add constraint emp_pk primary key(empno);

table altered.

sql>
sql>
sql> drop table emp_reg;

table dropped.

sql> --

补充：数据库,Oracle教程