Basic Concepts Data are represented by collections of records. similar to an entity in the E-R model Records and their fields are represented as record type type customer record type account record customer-name:string; account-number:integer; customer-street:string; balance:integer; customer-city:string; end end Relationships among data are represented by links similar to a restricted(binary)form of an E-R relationship restrictions on links depend on whether the relationship is many- many,many-to-one,or one-to-one. Database System Concepts,5th Ed. A.2 ©Silberschat乜，Korth and SudarshanDatabase System Concepts, 5 A.2 ©Silberschatz, Korth and Sudarshan th Ed. Basic Concepts Data are represented by collections of records. similar to an entity in the E-R model Records and their fields are represented as record type type customer = record type account = record customer-name: string; account-number: integer; customer-street: string; balance: integer; customer-city: string; end end Relationships among data are represented by links similar to a restricted (binary) form of an E-R relationship restrictions on links depend on whether the relationship is many￾many, many-to-one, or one-to-one