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📚 SUBQUERY IN CONDITION

A subquery in a condition is used to compare a value from the main query to the result of a subquery.
It allows dynamic filtering based on the results of another query.

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🛠️ Basic Syntax

SELECT column1, column2
FROM table_name
WHERE column_name operator (SELECT column_name FROM another_table WHERE condition);

• The operator can be =, IN, NOT IN, >, <, >=, <=, etc.
• The subquery must return a single value or a list depending on the operator used.

Example

SELECT first_name, last_name
FROM employees
WHERE department_id IN (SELECT department_id FROM departments WHERE location = 'New York');

• This query selects employees who work in departments located in New York.

Key Points

• If using =, the subquery must return only one value.
• If using IN, the subquery can return multiple values.
• Always ensure your subquery returns the right number of results for the operator.

Additional Example

SELECT product_name
FROM products
WHERE price > (SELECT AVG(price) FROM products);

• This query selects products that have a price greater than the average price of all products.

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🎥 Video Notes

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📝 Problem Description

Describe the problem, challenge, or topic discussed in a video related to SELECT FROM.
What concept was explained or what exercise was solved?

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DataBase Given

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💻 My SQL Code

-- Write your SQL code attempt or solution related to SQL COMMAND
SQL COMMAND

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🧠 Solution Code / Explanation

SQL COMMAND

Explanation - Explain what you learned, any key takeaways, or how you solved the problem related to COMMAND._

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