Web development quizzes

This query is correct: SELECT * FROM employee WHERE age IN (20,21,22);
False
True

This query is correct: SELECT column1 FROM table1 UNION SELECT column2 FROM table2;
False
True

A SELECT statement is a data definition language (DDL).
False
True

Indexes allow the database application to find data slowly.
False
True

A primary key column can contain NULL values.
False
True