Question

Which of the following is not a valid SQLite constraint?

a) NOT NULL

b) PRIMARY KEY

c) UNIQUE

d) FOREIGN KEY

Answer 1

Answer: d) FOREIGN KEY

Explanation: FOREIGN KEY is a valid constraint in SQLite. It is used to define a relationship between two tables. The syntax for adding a foreign key constraint is as follows: FOREIGN KEY (column_name) REFERENCES table_name(column_name);