data base system

sajid ali laghari

how i make the entity relation of "car selling and car purchase " plz help me about this question

Lost User

You draw an arrow from one entity to the other. Done. Did you mean in code? What database-system? Here's one in SQL92;

CREATE TABLE Car
(
cId INTEGER,
Description CHARACTER VARYING(50),
PRIMARY KEY (cId)
)

CREATE TABLE CarPurchase
(
pId INTEGER,
boughtCar INTEGER,
PRIMARY KEY (pId),
FOREIGN KEY (boughtCar) REFERENCES Car
)

This syntax should work on most systems.

Bastard Programmer from Hell :suss: