Relationships in Microsoft Access

Relationships are an integral part of any database, not just Microsoft Access, without it all you really have is a series of spread sheets, and at the point you may as well just use MS Excel or some other spread sheet program. Relationships are your best tool for preventing data redundancy and storing the data in your database as efficiently as possible. Relationships allow you to refer to data in other tables without having to duplicate it yourself, and if referential integrity is enabled it ensures the data is synced correctly. Not needing to duplicate data is useful as it prevents having to enter in data multiple times, meaning more time saved and less chance of human error. Even if there is a typo or other similar mistake in the original table, if referenced in multiple tables, you will only need to change the record once rather than how many times it is referenced, which in some databases could be in the hundreds of thousands.

Any Microsoft Access Database Developer or Consultant worth their salt would take full advantage of the power afforded by the relationships in Microsoft Access. On the surface, relationships probably seem relatively simple, but just like in the real world, relationships can be quite complex, although I haven’t heard of a clingy or cheating database yet. In Microsoft Access, there are three types of relationships, one-to-one (or monogamous if you want to continue the joke.), many-to-many and one-to-many. Essentially in a one-to-one relationship only one record in table A can reference one record in table B, in a many-to-many relationship you can have one record in table A refer to many records in table B and vice versa. Although many-to-many relationships need a third table containing the primary keys of table A and table B as its foreign key to work in MS Access. Finally a many-to one-relationship are where one record in table A refers to many in table B. At the end of the day, Microsoft Access Database Developers or Consultants have a very powerful tool in their arsenal, and they’d be foolish to not take advantage of the flexibility provided to them by it.