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', 'analyst', 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', 'analyst', 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  * 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> --