FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -In your Customers table, each record is identified by the primary key field, ID.

Detailed explanation-2: -A primary key is a field or set of fields with values that are unique throughout a table. Values of the key can be used to refer to entire records, because each record has a different value for the key. Each table can only have one primary key.

Detailed explanation-3: -A primary key is a column or a set of columns in a table whose values uniquely identify a row in the table. A relational database is designed to enforce the uniqueness of primary keys by allowing only one row with a given primary key value in a table.

Detailed explanation-4: -A primary key is a field in a table which uniquely identifies each row/record in a database table. Primary keys must contain unique values. A primary key column cannot have NULL values. A table can have only one primary key, which may consist of single or multiple fields.

Detailed explanation-5: -A primary key, also called a primary keyword, is a column in a relational database table that’s distinctive for each record. It’s a unique identifier, such as a driver’s license number, telephone number with area code or vehicle identification number (VIN). A relational database must have only one primary key.