[Solved] Given the table employees with columns department and salary, what does this query return?SELECT department, COUNT(*), AVG(salary) FROM employees GROUP BY department; | SQL

SQL - Aggregate Functions

Given the table employees with columns department and salary, what does this query return?

SELECT department, COUNT(*), AVG(salary) FROM employees GROUP BY department;

AList of departments without any aggregation

BTotal salary and employee count for all departments combined

CNumber of employees and average salary per department

DSyntax error due to missing WHERE clause

Step-by-Step Solution

Solution:

Step 1: Analyze GROUP BY usage
GROUP BY department groups rows by department for aggregation.
Step 2: Understand aggregates COUNT and AVG
COUNT(*) counts employees per department; AVG(salary) calculates average salary per department.
Final Answer:
Number of employees and average salary per department -> Option C
Quick Check:
GROUP BY + COUNT + AVG = grouped summaries [OK]

Quick Trick: GROUP BY groups rows; aggregates summarize per group [OK]

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