[Solved] Find the problem in this query:SELECT STRING_AGG(name, ',') FROM employees GROUP BY department;Assuming name and department columns exist. | PostgreSQL

PostgreSQL - Aggregate Functions and GROUP BY

Find the problem in this query:
SELECT STRING_AGG(name, ',') FROM employees GROUP BY department;
Assuming name and department columns exist.

AMissing alias for STRING_AGG result

BNo error, query is valid

CSTRING_AGG cannot be used with GROUP BY

DSeparator must be a space, not a comma

Step-by-Step Solution

Solution:

Step 1: Understand STRING_AGG with GROUP BY
STRING_AGG is often used with GROUP BY to aggregate strings per group.
Step 2: Check query validity
The query syntax is correct; alias is optional, separator ',' is valid.
Final Answer:
No error, query is valid -> Option B
Quick Check:
STRING_AGG works with GROUP BY [OK]

Quick Trick: STRING_AGG commonly used with GROUP BY [OK]

Common Mistakes:

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