SQL FULL JOIN Quiz

What is the primary purpose of the SQL FULL JOIN?

• To combine rows from two tables where there are matches in both.

• To retrieve all rows from both tables, regardless of matches.

• To retrieve only rows from the left table that have matches in the right table.

• To retrieve only rows from the right table that have matches in the left table.

How does a FULL JOIN differ from an INNER JOIN?

• FULL JOIN returns all rows from both tables, while INNER JOIN only returns matching rows.

• FULL JOIN returns only matching rows, while INNER JOIN returns all rows from both tables.

• FULL JOIN is faster than INNER JOIN.

• FULL JOIN is used for more complex queries than INNER JOIN.

What happens when there is no match between rows in a FULL JOIN?

• The query returns an error.

• The unmatched rows are omitted from the result.

• The unmatched rows are included in the result with NULL values for the missing columns.

• The unmatched rows are included in the result with empty strings for the missing columns.

What is the syntax for a FULL JOIN in SQL?

• SELECT columns FROM table1 FULL JOIN table2 ON table1.column = table2.column;

• SELECT columns FROM table1 JOIN table2 ON table1.column = table2.column;

• SELECT columns FROM table1 LEFT JOIN table2 ON table1.column = table2.column;

• SELECT columns FROM table1 RIGHT JOIN table2 ON table1.column = table2.column;

Which of the following is a correct way to perform a FULL JOIN on three tables?

• SELECT * FROM table1 FULL JOIN table2 FULL JOIN table3 ON table1.column = table2.column AND table2.column = table3.column;

• SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column FULL JOIN table3 ON table2.column = table3.column;

• SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column INNER JOIN table3 ON table2.column = table3.column;

• SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column LEFT JOIN table3 ON table2.column = table3.column;

How can you filter the results of a FULL JOIN using a WHERE clause?

• By specifying conditions on the columns from both tables.

• By specifying conditions only on the columns from the left table.

• By specifying conditions only on the columns from the right table.

• By specifying conditions only on the join condition.

Which of the following is a valid use case for a FULL JOIN?

• Combining customer data with order data to get a complete view of customer purchases.

• Retrieving all employees and their corresponding departments.

• Finding all products that have been sold in the last month.

• Identifying all students who have not borrowed any books from the library.

What is the difference between a FULL JOIN and a FULL OUTER JOIN?

• FULL JOIN is a synonym for FULL OUTER JOIN.

• FULL JOIN is more efficient than FULL OUTER JOIN.

• FULL JOIN is used for specific databases, while FULL OUTER JOIN is used for others.

• There is no difference.

What is the main advantage of using a FULL JOIN?

• It is faster than other join types.

• It provides a complete view of data from both tables, including unmatched rows.

• It is easier to understand than other join types.

• It is more flexible than other join types.

What is a common use case for a FULL JOIN with a WHERE clause?

• Combining data from multiple tables and filtering based on a specific condition.

• Identifying missing data from one of the tables.

• Analyzing data from different time periods.

• All of the above.