Which term represents a unique identifier for a record within a table?

Which term represents a unique identifier for a record within a table?

• A. Primary key
• B. Foreign key
• C. Rows/records
• D. Fields/columns

Answer: (A)

The unique identifier for a record within a table is the primary key. It serves to distinguish every row from every other row, with values that are unique and typically not null, so you can always reference a specific record unambiguously. This key is what you rely on to join tables and enforce entity integrity. A foreign key, by contrast, points to a primary key in another table to establish a relationship; it isn’t required to be unique in its own table and doesn’t serve as the table’s unique row identifier. Rows or records are the actual data entries, while fields or columns are the individual attributes stored for each row.

The unique identifier for a record within a table is the primary key. It serves to distinguish every row from every other row, with values that are unique and typically not null, so you can always reference a specific record unambiguously. This key is what you rely on to join tables and enforce entity integrity. A foreign key, by contrast, points to a primary key in another table to establish a relationship; it isn’t required to be unique in its own table and doesn’t serve as the table’s unique row identifier. Rows or records are the actual data entries, while fields or columns are the individual attributes stored for each row.