______ is NOT a type of constraint in SQL language?

Category: SQL______ is NOT a type of constraint in SQL language?
Editor">Editor Staff asked 2 years ago

______ is NOT a type of constraint in SQL language?

  1. FOREIGN KEY
  2. PRIMARY KEY
  3. UNIQUE
  4. ALTERNATE KEY
1 Answers
Editor">Editor Staff answered 2 years ago

Answer:
ALTERNATE KEY
Explanation: ALTERNATE KEY is a key associated with one or more columns to identify each row in a table uniquely. If a table with one or more candidate keys, then the keys other than the primary key is an alternate key. Since the alternate key is a part of the candidate key, it is not a constraint in SQL. Hence, option D is the correct choice.