Common Types of Relationships
Previously, we discussed one-to-many relational databases. By far, this is the most common type of data relationship that we encounter. We discussed parents and children. A parent record can have many child records, but a child record belongs to one and only one parent record. Those relationships are defined through data. A parent record has a primary key that is assigned when a record is created. A child record displays part of the DNA of its parent by carrying the unique parent ID in a foreign key field. When the child’s foreign key value matches the parent’s primary key value we have a link between those records.
Other types of relationships occur as well. In this article, we’ll cover one-to-one and many-to-many database relationships.