fremmednøkkelverdiene
Fremmednøkkelverdiene, often translated as foreign key values, are a fundamental concept in relational database design. They represent the values in one table that correspond to the primary key values in another table. This linkage is crucial for establishing and enforcing relationships between different tables within a database. When a foreign key constraint is defined, it ensures referential integrity, meaning that a value entered into the foreign key column must already exist in the primary key column of the referenced table.
For example, in a database for an online store, a 'customers' table might have a 'customer_id' as
Fremmednøkkelverdiene facilitate data consistency, prevent orphaned records (records in one table without a corresponding record in