Oracle中修改列的方法

1.add

ALTER TABLE table_name ADD( column datatype [DEFAULT EXPR][,column datatype...]);

SQL>ALTER TABLE test ADD id NUMBER;

2.modify

SQL>ALTER TABLE test MODIFY id VARCHAR2(15);

3.delete

SQL> ALTER TABLE test DROP COLUMN id;

4.rename col

SQL>ALTER TABLE test RENAME COLUMN id TO nid;

5.rename table

SQL>RENAME test TO test1;

6.add comment

SQL>COMMENT ON TABLE test IS 'for test';

SQL>COMMENT ON TABLE test.id IS 'id number';