Database: How many primary key constraints can be created for one table?

USER_CONSTRAINTS (More...)

USER_CONSTRAINTS (More...)

Yes, view can update or delete from underlying tables. (More...)

c) (More...)

ALTER TABLE table_name
ADD UNIQUE (Column_Name) (More...)

ALTER TABLE table_name
ADD CHECK (P_Id>0) (More...)

DROP option in the ALTER TABLE command is used to drop constraints specified on the table. (More...)

select city_name
from areas
group by city_name

having count(*) > 1 (More...)

select * from INFORMATION_SCHEMA.tables where table_name like 'tblname%' (More...)

we can get primary key information with the following SQL statement

SELECT b.table_name, b.column_name, b.position, a.status, cons.owner
FROM all_constraints a, all_cons_columns b
WHERE cons.constraint_type = 'P'
AND a.constraint_name = b.constraint_name
AND a.owner = b.owner
ORDER BY b.table_name, b.position;
(More...)