Quizzes de desarrollo web

This query retrieves the first 3 rows: SELECT * FROM employee LIMIT 3;
False
True

UNIQUE and NOT NULL are contraints.
False
True

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

There are different versions of the SQL language.
False
True

AVG() returns the average of a numeric column.
False
True