SQL Trap: WHERE vs HAVING with GROUP BY (Interview Question Explained)

Most SQL interviews quietly test if you really understand WHERE vs HAVING with GROUP BY – and if you mix them up, your answer is either wrong or you hit errors.
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In this video, we take a simple Sales table with region, sale_month, and amount and solve this real interview‑style question:

“Show each region’s total sales, but only keep the regions whose total sales are greater than 10,000.”

You’ll see:
– Why WHERE SUM(amount) greater than 10000 doesn’t work.
– Why WHERE amount greater than 10000 is syntactically correct but logically wrong for the question.
– The correct solution using HAVING SUM(amount) greater than 10000 after GROUP BY region.
– How the order of execution works: FROM → WHERE → GROUP BY → HAVING → SELECT.
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We then go further and show:
– When to use WHERE (row‑level filter).
– When to use HAVING (aggregate/group‑level filter).
– How to combine WHERE, GROUP BY, and HAVING in one query for questions like “only January sales greater than 5,000 per region”.
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This is a must‑know concept for SQL interviews (data analyst, data engineer, BI, backend dev) and for writing correct reports in real projects.
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🔽 Try it yourself
I’ve used a simple Sales table with regions (North, South, East, West) and monthly amounts. You can recreate it with the script in the comments/description and practice the queries shown in this video.
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If this helped you finally understand WHERE vs HAVING, like the video, subscribe to SQLWithAsif, and share it with someone preparing for SQL interviews.

#sql #sqltutorial #sqlinterview #sqlwithasif #wherevshaving #groupby #dataanalytics #dataengineer
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Script for table
-- Drop if exists (SQL Server syntax; remove if not needed)
IF OBJECT_ID('dbo.Sales', 'U') IS NOT NULL
DROP TABLE dbo.Sales;

-- Base table
CREATE TABLE dbo.Sales (
sale_id INT IDENTITY(1,1) PRIMARY KEY,
region VARCHAR(20),
sale_month VARCHAR(10),
amount INT
);

-- Sample data
INSERT INTO dbo.Sales (region, sale_month, amount) VALUES
-- North: total 11,000
('North', 'Jan', 4000),
('North', 'Feb', 7000),

-- South: total 12,000
('South', 'Jan', 3000),
('South', 'Feb', 9000),

-- East: total 3,500
('East', 'Jan', 2000),
('East', 'Feb', 1500),

-- West: total 13,000
('West', 'Jan', 6000),
('West', 'Feb', 7000);

Видео SQL Trap: WHERE vs HAVING with GROUP BY (Interview Question Explained) канала SQLWithAsif