Methods Can add a method declaration with a structured type. method ageOnDate (onDate date) returns interval year Method body is given separately. create instance method ageOnDate (onDate date) returns interval year for CustomerType begin return onDate-self.dateOfBirth: end We can now find the age of each customer: select name.lastname,ageOnDate(current_date) from customer Database System Concepts-6th Edition 22.10 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 22.10 ©Silberschatz, Korth and Sudarshan th Edition Methods Can add a method declaration with a structured type. method ageOnDate (onDate date) returns interval year Method body is given separately. create instance method ageOnDate (onDate date) returns interval year for CustomerType begin return onDate - self.dateOfBirth; end We can now find the age of each customer: select name.lastname, ageOnDate (current_date) from customer