Quick Answer

Using WHERE to select specific rows

Understanding the Issue

The WHERE clause filters records to include only those that meet specified conditions. It comes after FROM and before GROUP BY/ORDER BY clauses.

The Problem

This code demonstrates the issue:

Sql Error 
-- Problem: Need to filter products
SELECT * FROM products; -- All products

The Solution

Here's the corrected code:

Sql Fixed 
-- Solution 1: Basic filtering
SELECT * FROM products WHERE price > 50;

-- Solution 2: Multiple conditions
SELECT * FROM products 
WHERE price > 50 AND category = 'Electronics';

-- Solution 3: Pattern matching
SELECT * FROM products 
WHERE name LIKE '%Phone%';

-- Solution 4: NULL handling
SELECT * FROM customers WHERE phone IS NOT NULL;

Key Takeaways

Use WHERE to efficiently filter data before processing.