Question

A primary key in a database is a ________.

A) group of rows that identifies a unique table or file
B) column or group of columns that identifies a unique row in a table
C) group of fields or columns that represent metadata
D) group of tables or files formed to identify a unique field or row

Answer 1

A primary key in a database uniquely identifies each row within a table and is crucial for data integrity.

Step-by-step explanation:

A primary key in a database is a column or group of columns that identifies a unique row in a table. This key is crucial for maintaining data integrity within the database. Each table has a primary key, and each entry within the table can be uniquely identified by the values in this key. For instance, in a student database, the student ID might be the primary key because each student has a unique ID. No two rows can have the same primary key values, which prevents duplicate records and helps in efficiently locating specific records.