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ALTER TABLE AA DROP UNUSED COLUMNS;
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alter table table_name add mmm varchar2(10);
update table_name set mmm=** ;
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insert into t_address (addressname) (select vcname from busstop)
create sequence seq_id_test_increment --ÐòÁÐ
increment by 1 start with 1 maxvalue 9999999;
create or replace trigger insert_test_increment --´¥·¢Æ÷
before insert on t_address --t_address ±í
referencing
new as new
old as old
for each row
begin
select seq_id_test_increment.nextval into :new.addressid from dual; --addressid×Ö¶Î
end;
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create or replace trigger del_dept_id
after delete on dept
for each row
begin
delete from emp where deptno=:old.deptno;
end;
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