Thread: Primary Key
04-22-04, 06:53 #1Registered User
- Join Date
- Apr 2004
Unanswered: Primary Key
In the database that i have i use an auto number as a primary key. The database links various tables with the primary key ensuring that the correct medical conditions go along with the correct personal details. i.e
Patient number 3 is linked by the primary key to the patient 3's medical conditions.
A problem arises however when a mistake is made so that a record in the personal details is created and a record is not created in the medical conditions i.e
patient id 5 is created in personal details but a mistake is made and the information is deleted. The next record will automatically be patient id 6 and not five. This then means that patient id 6 will have id number 5 in medical conditions and therefore will not have the correct medical information.
Can anybody help me with this problem as it is effecting the accuracy of my database
04-22-04, 07:18 #2Registered User
- Join Date
- Sep 2003
- The extremely Royal borough of Kensington, London
Foreign Key constraints will solve the problem.
TableA(id) Primary key(id);
TableB(id) Foreign Key (id) References TableA(id);Bessie Braddock: Winston, you are drunk!
Churchill: And Madam, you are ugly. And tomorrow, I'll be sober, and you will still be ugly.