[Solved] What does the GROUP BY clause do in a PostgreSQL query? — Ans: It groups rows that have the same values in specified columns. | PostgreSQL

PostgreSQL - Aggregate Functions and GROUP BY

What does the GROUP BY clause do in a PostgreSQL query?

AIt updates values in the specified columns.

BIt sorts the rows in ascending order.

CIt deletes duplicate rows from the table.

DIt groups rows that have the same values in specified columns.

Step-by-Step Solution

Solution:

Step 1: Understand the purpose of GROUP BY
The GROUP BY clause collects rows that share the same value in one or more columns into groups.
Step 2: Differentiate from other clauses
Unlike ORDER BY which sorts rows, GROUP BY organizes rows into groups for aggregation.
Final Answer:
It groups rows that have the same values in specified columns. -> Option D
Quick Check:
GROUP BY = groups rows by column values [OK]

Quick Trick: GROUP BY collects rows sharing column values into groups [OK]

Common Mistakes:

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What does the GROUP BY clause do in a PostgreSQL query?