Question

Which fields in a table are required fields by definition? Select one:

a. A field with a default value
b. A field with a primary key
c. A field with a lookup List.
d. A field with an input mask functions refers to using one function within another one

Answer 1

A field with a primary key is a required field in a database table because it uniquely identifies each record and cannot be null, ensuring table integrity.

Step-by-step explanation:

By definition, the fields in a table that are required fields are the ones that cannot be left empty. In the context of a database table, a field with a primary key is a required field. A primary key uniquely identifies each record in the table, and it cannot contain a NULL value, which makes it essential for maintaining the integrity of the table. Hence, it fulfills the criteria of a required field.

Option A, a field with a default value, is not necessarily required because it automatically fills in a predefined value when a new record is inserted without a specified value for that field. Option C, a field with a lookup list, is also not automatically required; it's simply a field that allows users to choose a value from a set instead of typing it manually, which can help with data consistency but doesn't make the field required. Lastly, option D, a field with an input mask, is used to govern the format of data entry, such as phone numbers or social security numbers, but this also does not inherently make a field required.