Oracle PL/SQL/System Tables Views/user unused col tabs — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Версия 16:45, 26 мая 2010
Query user_unused_col_tabs
<source lang="sql">
create table people(
employee_id number(9), first_name varchar2(15), last_name varchar2(20), email varchar2(25), constraint pk_people primary key (employee_id)
); insert into people values (1, "T", "Kyte", "Y@q.ru"); insert into people values (2, "S", "Viper","s@q.ru"); insert into people values (3, "C", "Beck", "c@q.ru");
alter table people drop column first_name; alter table people drop column last_name; select * from user_unused_col_tabs; ALTER TABLE people DROP UNUSED COLUMNS; drop table people;
</source>