What are boolean operations in database queries?

What are boolean operations in database queries?

Boolean operations in database queries refer to the use of logical operators like AND, OR, and NOT to filter data.

Can you give me an example of how to use AND in a SQL query?

Sure! In a SQL query, you might use AND like this: SELECT * FROM users WHERE age > 18 AND city = 'New York'; This retrieves users older than 18 who live in New York.

What about using OR? How does that work?

Using OR allows you to retrieve records that meet at least one of the conditions. For example: SELECT * FROM users WHERE city = 'New York' OR city = 'Los Angeles'; This gets users from either city.

How does NOT work in a query?

The NOT operator excludes records that meet a certain condition. For example: SELECT * FROM users WHERE NOT city = 'Chicago'; This retrieves users who do not live in Chicago.