[Solved] Identify the error in this SQL query:SELECT name, age FROM users WHERE age > 18 GROUP BY name; — Ans: GROUP BY should include all selected columns or use aggregation. | SQL

SQL - Advanced Query Patterns

Identify the error in this SQL query:

SELECT name, age FROM users WHERE age > 18 GROUP BY name;

AThe query is correct as written.

BWHERE clause cannot be used with GROUP BY.

CSELECT must include only columns in GROUP BY.

DGROUP BY should include all selected columns or use aggregation.

Step-by-Step Solution

Solution:

Step 1: Review SELECT and GROUP BY rules
When using GROUP BY, all selected columns must be grouped or aggregated.
Step 2: Check the query columns
The query selects name and age but only groups by name, so age is neither grouped nor aggregated.
Final Answer:
GROUP BY should include all selected columns or use aggregation. -> Option D
Quick Check:
All selected columns must be in GROUP BY or aggregated [OK]

Quick Trick: All selected columns must be grouped or aggregated [OK]

Common Mistakes:

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