CTE referencing another CTE in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a CTE named 'first_cte' that selects all columns from the 'employees' table.

SQL

WITH first_cte AS (SELECT * FROM [1]) SELECT * FROM first_cte;

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

Adepartments

Bemployees

Csalaries

Dprojects

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a table other than 'employees' will cause the query to return wrong data or error.

The CTE 'first_cte' must select from the 'employees' table, so the correct answer is 'employees'.

2fill in blank

medium

Complete the code to define a second CTE named 'second_cte' that selects only the 'id' and 'name' columns from 'first_cte'.

SQL

WITH first_cte AS (SELECT * FROM employees), second_cte AS (SELECT [1] FROM first_cte) SELECT * FROM second_cte;

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

Asalary, department

Bid, salary

Cname, department

Did, name

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting columns not present in 'first_cte' will cause errors.

The second CTE selects 'id' and 'name' columns from 'first_cte'.

3fill in blank

hard

Fix the error in the code by choosing the correct keyword to reference the first CTE inside the second CTE.

SQL

WITH first_cte AS (SELECT * FROM employees), second_cte AS (SELECT id, name FROM [1]) SELECT * FROM second_cte;

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

Afirst_cte

Bdepartments

Csecond_cte

Demployees

Attempts:

3 left

💡 Hint

Common Mistakes

Referencing the base table or wrong CTE name causes errors.

The second CTE must reference the first CTE by its name 'first_cte'.

4fill in blank

hard

Fill both blanks to complete the query that defines two CTEs where the second CTE filters employees with salary greater than 50000.

SQL

WITH first_cte AS (SELECT * FROM [1]), second_cte AS (SELECT id, name FROM first_cte WHERE [2] > 50000) SELECT * FROM second_cte;

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

Aemployees

Bdepartments

Csalary

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table or column names causes errors or wrong results.

The first CTE selects from 'employees'. The second CTE filters where 'salary' is greater than 50000.

5fill in blank

hard

Fill all three blanks to complete the query that defines three CTEs: first selects employees, second filters by department 'Sales', third selects names and salaries above 60000.

SQL

WITH first_cte AS (SELECT * FROM [1]), second_cte AS (SELECT * FROM first_cte WHERE [2] = 'Sales'), third_cte AS (SELECT [3] FROM second_cte WHERE salary > 60000) SELECT * FROM third_cte;

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

Aemployees

Bdepartment

Cname, salary

Did, salary

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong column names or selecting wrong columns causes errors or wrong output.

The first CTE selects from 'employees'. The second filters where 'department' equals 'Sales'. The third selects 'name' and 'salary' columns.