Question

7.1. the following table with purchase orders is created: create table purchase order(ponr char(7) not null primary key, podate date,supnr char(4) not null, a. all purchase order records tied to that supplier are also deleted. b. the supnr of this supplier is replaced by a null value inpurchase order. c. the supnr of this supplier is deleted in purchase order. d. the supnr of this supplier is only deleted in supplier.foreign key (supnr) referencessupplier (supnr)on delete cascade on updatecascade);what happens upon deletion of a supplier?

Answer 1

Upon deletion of a supplier:

a. All purchase order records tied to that supplier are also deleted due to the "on delete cascade" constraint in the foreign key relationship.

How to explain

b. The supnr of this supplier is replaced by a null value in the purchase order table due to the "on delete set null" action in the foreign key constraint.

c. The supnr of this supplier is deleted in the purchase order table, leaving corresponding purchase order records without a supplier.

d. The supnr of this supplier is only deleted in the supplier table, affecting the supplier record without impacting related purchase order records due to the "on delete cascade" constraint.