What is the SQL keyword used to specify that a column can contain NULL values?OptionsALLOW NULLNOT NULLNULL ABLEWITH NULLS

What is the purpose of the NULL value in SQL? *It represents an empty string.It represents a missing or unknown value.It represents the absence of a primary key.It represents a zero value.

Which is the SQL constraint that allows inputting NULL in a specified column in a DBMS table but that does not allow inputting the already entered value?

In SQL, which operator is used to check if a value is within a specified range?OptionsINLIKEIS NULLBETWEEN

What is a NULL Value?A NULL value is a zero valueA NULL value is a field that contains spacesA field with a NULL value is a field with no value.A NULL value is different from a zero value or a field that contains spaces

A NOT NULL __________ is a rule that prevents certain fields in a database from being left blank.answerscalabilityschemaquery builderconstraint