Which of the following demonstrates the correct way to perform an UPDATE using a writable CTE in PostgreSQL?

easy📝 Syntax Q3 of 15

PostgreSQL - Common Table Expressions

AWITH updated AS (UPDATE employees SET salary = salary * 1.1 WHERE department = 'Sales' RETURNING *) SELECT * FROM updated;

BWITH updated AS (SELECT * FROM employees WHERE department = 'Sales') UPDATE employees SET salary = salary * 1.1 WHERE department = 'Sales';

CUPDATE employees SET salary = salary * 1.1 WHERE department = 'Sales' WITH updated AS RETURNING *;

DWITH updated AS (UPDATE employees SET salary = salary * 1.1) SELECT * FROM employees WHERE department = 'Sales';

Step-by-Step Solution

Solution:

Step 1: Use a writable CTE with UPDATE and RETURNING
The writable CTE must include the UPDATE statement followed by a RETURNING clause to capture updated rows.
Step 2: Select from the CTE
After the CTE, a SELECT statement retrieves the updated rows from the CTE alias.
Final Answer:
WITH updated AS (UPDATE employees SET salary = salary * 1.1 WHERE department = 'Sales' RETURNING *) SELECT * FROM updated; -> Option A
Quick Check:
Writable CTEs require RETURNING to output updated rows [OK]

Quick Trick: Writable CTE UPDATE needs RETURNING clause [OK]

Common Mistakes:

Master "Common Table Expressions" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free