Database Management A Referential Integrity Constraint - 275 Words

Database Management: A Referential Integrity Constraint (Essay Sample) Content: DATABASE SCHEMANAME OF STUDENTNAME OF SCHOOLSUBMITTED TODATEProducts (id: integer, title: string, price: float, quantity: integer, category: string, supplier: string)Customers (id: integer, cname: string, address: string, telephone: string, email: string)Suppliers (sid: integer, sup_name: string, address: string, city: string, province: string, postal_code: string)Orders (order_id, integer, cust_id: integer, order_date: string, order_status: string, total: float)ItemsPurchased (order_id: integer, product_id: integer, quantity: integer, price: float, total: float) * Select a primary key(s) for each of these relationsProducts - idCustomers - idSuppliers - sidOrders - order_idItemsPurchased- order_id * Is the condition (id, cname) a key for the Customer relation?Yes. The id  acts as the primary key for the relation. However, the cname  could have duplicates and can therefore be viewed as a alternative or secondary key. * Is the condition (id, cname) a candidate key for the Customer relation?Yes. The condition can be used to uniquely identify any tuple without referring to any other within the relation. * Define all possible foreign keys for the relations.Products id, supplierCustomer idSupplier sidOrders cust_idItemsPurchased order_id, product_id * Give an example of a tuple that the DBMS would reject because it would violate a uniqueness constraintRelation: product id title price quantity category supplier 1 1254 machinery 3000.00 200 H.G Donald 2 1254 machinery 3000.00 200 H.G Donald * Give an example of a tuple that the DBMS would reject because it would violate a referential integrity constraintForeign key (Product_Id)Relation 1: Items Purchased Order_id Product_id quantity Price total 1 466559 1254 70 350 800 2 466255 1448