[Solved] Identify the error in this query:SELECT department, COUNT(employee_id) FROM employees; — Ans: Missing GROUP BY clause for department | SQL

SQL - GROUP BY and HAVING

Identify the error in this query:

SELECT department, COUNT(employee_id) FROM employees;

ASELECT must include WHERE clause

BMissing GROUP BY clause for department

CCOUNT cannot be used with employee_id

Demployee_id should be in HAVING clause

Step-by-Step Solution

Solution:

Step 1: Analyze the SELECT and aggregation
The query selects department and counts employee_id but lacks grouping.
Step 2: Understand SQL rules for aggregation
When using aggregate functions with other columns, those columns must be in GROUP BY.
Final Answer:
Missing GROUP BY clause for department -> Option B
Quick Check:
Aggregate + column needs GROUP BY [OK]

Quick Trick: Use GROUP BY with non-aggregated columns [OK]

Common Mistakes:

MISTAKES

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