hi all. Imagine a situation. There is a big company which has many service centers. These service centers provide different service types - some of them replace car tires, others repair engines, and other ones fill petrol or another fuel. No we have the following: Table of service centers ------------------------ ID name address Table of service types ---------------------- ID name Table of work types ------------------- ID service_type_ID name Now i bind service centers and service types bind_table -------------------------------------------- service_center_ID service_type_ID And now i want to log which works were done on each service center Table "works" ------------- ID (to refer it later in material consumption table etc...) date_time (date when the work was done) service_center_ID work_type_ID Seems like it's ok, but it is possible to write incorrect record for example work "tire replacement" on service point which only repairs engines (as specified in bind_table). Is it possible to avoid such errors at database level?