Primary Key
The primary key is a unique identifier for a record. The primary key cannot be the same for two records. This field can never be blank.
The primary key is a unique identifier for a record. The primary key cannot be the same for two records. This field can never be blank.
Composite Key
A composite key is a primary key that is comprised of two or more fields. It can also be called a compound or concatenated key.
A composite key is a primary key that is comprised of two or more fields. It can also be called a compound or concatenated key.
Foreign Key
A foreign key is a field or combination of fields that are related to the primary key of another table.
A foreign key is a field or combination of fields that are related to the primary key of another table.
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