Also called a Key field.
A primary key is one that uniquely identifies a record . Also there are cases when primary key of one file appears in another file. In that case the key is called Foreign key.
Primary Sort Key
A foreign key is a field in a database table that is used to establish a relationship with another table. It ensures referential integrity by enforcing a link between two tables based on a matching key. This key is typically a primary key in the referenced table.
A foreign key is when a value of one table, which is a primary key of another table. Manufacturer_table - id - name Models_table - id - manufacturer_id - name Models_table.manufacturer_id should be defined is a foreign key to the Manufacturer_table.id column
In some cases, a last name can be used as a primary key if it uniquely identifies each record in a dataset. However, it is generally not recommended to use a last name as a primary key due to the potential for duplication or changes over time. It is often better to use a combination of attributes to create a more robust primary key.
Primary Sort key
A First name field is not a good one for a primary key. A primary key cannot have duplicate values. A first name field is highly likely to have duplicate values, so it should not be used as a primary key.
It is the DBMS that ensures the value of the foreign key matches another table's primary key when referential integrity constraints are enabled within the DBMS
primary key
A primary key is an attribute (or combination of attributes) that uniquely identifies each row in a relation. A primary key is designated by underlining the attribute name. The primary key of an entity set allows us to distinguish among the various entities of the set. A foreign key is an attribute in a relation of database that serves as the primary key of another relation in the same database.
Foreign Key