Mastering SQL Joins and Filters

What type of SQL join returns all records from the left table and the matched records from the right table, with nulls in place where there is no match?

• INNER JOIN

• LEFT JOIN

• RIGHT JOIN

• FULL JOIN

Which SQL clause is used to filter records that meet a certain condition?

• ORDER BY

• GROUP BY

• WHERE

• HAVING

Consider two tables, `Students` and `Courses`. To find all students who have not enrolled in any course, which SQL join would you use?

• INNER JOIN

• LEFT JOIN

• RIGHT JOIN

• FULL JOIN

Which SQL statement will return all records from both tables and fill in nulls for missing matches?

• SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id;

• SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id;

• SELECT * FROM table1 RIGHT JOIN table2 ON table1.id = table2.id;

• SELECT * FROM table1 FULL JOIN table2 ON table1.id = table2.id;

If you want to filter results based on an aggregate function, which SQL clause should you use?

• WHERE

• ORDER BY

• GROUP BY

• HAVING