[Anglika]

Originally Posted by fahimaamir

sir
Please check these material also an correct.
No check code check only my description that I wrote
1.)

Table
"Table" is a set of data elements that is organized in rows and columns.
The columns are identified by name and are the fields; the rows are identified by values appearing in specific column subsets are are called the records. The tables are linked with each other by candidate key.

Create Degreedim table


This flowing code creates a DEGREEDIM table in which is saved the department and degree information

CODE :

CREATE TABLE DEGREEDIM( "DEGDEPT" VARCHAR2(99 BYTE), "DEGSNO" NUMBER NOT NULL ENABLE, "DEGNAME" VARCHAR2(99 BYTE),


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2.)

Constraint
"Constraint" is the table attribute used to define rules on the type of data value allowed within specified columns. By enforcing these rules within the database, you restrict to a user, preventing incorrect data being added to the database.

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3.)

Sequence
A "sequence" is an object in Oracle that is used to generate a number sequence. This sequence provides the unique number for the primary key


MDEG SequenceThis flowing code generate the unique number sequencecodeREM START MFAFORBI MDEGCREATE SEQUENCE "MFAFORBI"."MDEG" MINVALUE 1 MAXVALUE 999999999999999999999999999 INCREMENT BY 1 START WITH 41 CACHE 20 NOORDER NOCYCLE ;REM END MFAFORBI MDEG


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4.)

Trigger
"Trigger" is a special kind of stored procedure that executes automatically when a user attempts the specified insertion or update, or tries to delete a statement.
There are two types of trigger.

• Before (run before table affection)
• After (run after table affection)

Create DTTR Trigger

This flowing code gets a unique number from Mdeg sequence that is used as primary key in the DEGREEDIM table.

CODE :

CREATE OR REPLACE TRIGGER "MFAFORBI"."DTTR" BEFORE INSERT ON DEGREEDIM FOR EACH ROW BEGINSELECT MDEG.NEXTVAL INTO :NEW.DEGSNO FROM DUAL;END;

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Some sentences were very obscure. Check carefully that you understand my suggested alterations.