Set operations with ORDER BY in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to combine two tables and order the results by the column 'name'.

SQL

SELECT name FROM employees UNION SELECT name FROM managers ORDER BY [1];

Drag options to blanks, or click blank then click option'

Aname

Bsalary

Cid

Ddepartment

Attempts:

3 left

💡 Hint

Common Mistakes

Using a column not selected in the query for ORDER BY.

Forgetting to specify the column in ORDER BY.

The ORDER BY clause sorts the combined results by the 'name' column.

2fill in blank

medium

Complete the code to get all unique product IDs from two tables and order them in descending order.

SQL

SELECT product_id FROM sales UNION SELECT product_id FROM returns ORDER BY [1] DESC;

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Aquantity

Bcustomer_id

Cdate

Dproduct_id

Attempts:

3 left

💡 Hint

Common Mistakes

Ordering by a column not in the SELECT list.

Using ASC instead of DESC when descending order is required.

The ORDER BY clause sorts the combined unique product IDs in descending order.

3fill in blank

hard

Fix the error in the query by completing the ORDER BY clause to sort by 'score'.

SQL

SELECT user_id, score FROM game1 INTERSECT SELECT user_id, score FROM game2 ORDER BY [1];

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Alevel

Buser_id

Cscore

Ddate

Attempts:

3 left

💡 Hint

Common Mistakes

Ordering by a column not selected in the query.

Using a column from only one SELECT statement.

The ORDER BY clause must use a column from the SELECT list. Here, sorting by 'score' is correct.

4fill in blank

hard

Fill both blanks to combine two tables with UNION ALL and order by 'date' ascending and 'amount' descending.

SQL

SELECT date, amount FROM payments UNION ALL SELECT date, amount FROM refunds ORDER BY [1] ASC, [2] DESC;

Drag options to blanks, or click blank then click option'

Adate

Bamount

Ccustomer_id

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the order of columns in ORDER BY.

Using columns not selected in the query.

The query orders results first by 'date' ascending, then by 'amount' descending.

5fill in blank

hard

Fill all three blanks to combine two tables with EXCEPT and order by 'category' ascending, 'price' ascending, and 'stock' descending.

SQL

SELECT category, price, stock FROM inventory1 EXCEPT SELECT category, price, stock FROM inventory2 ORDER BY [1] ASC, [2] ASC, [3] DESC;

Drag options to blanks, or click blank then click option'

Acategory

Bprice

Cstock

Dsupplier

Attempts:

3 left

💡 Hint

Common Mistakes

Using columns not in the SELECT list for ORDER BY.

Incorrect order or direction in ORDER BY clauses.

The query orders results by 'category' ascending, then 'price' ascending, and finally 'stock' descending.