PLSQL CHECK CONSTRAINT

Why can i use check constraints ?

  • Data restriction
  • Data format
  • Control than other columns

CREATE
CREATE TABLE suppliers
(
  supplier_id numeric(4),
  supplier_name varchar2(50),
  quantity number,
  CONSTRAINT check_quantity
  CHECK (quantity > 0)
);

ALTER
ALTER TABLE suppliers
ADD CONSTRAINT check_supplier_name
  CHECK (supplier_name IN ('APPLE', 'SAMSUNG', 'NOKIA'));

Drop
ALTER TABLE suppliers
DROP CONSTRAINT check_supplier_id;

Enable
ALTER TABLE suppliers
ENABLE CONSTRAINT check_supplier_id;

Disable
ALTER TABLE suppliers
DISABLE CONSTRAINT check_supplier_id;


Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: