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Asked: 2024-09-26T18:27:37+05:30 In:

how to do or in sql

I’ve been trying to write a SQL query for a project at work, but I’m running into a bit of confusion regarding the use of the “OR” operator. I understand that “OR” is used to combine multiple conditions within a WHERE clause, but I’m not entirely sure how to structure it correctly. For instance, I need to filter results based on two different criteria: say, I want to select all employees who are either in the ‘Sales’ department or have a salary greater than $70,000.

I’ve attempted a few variations, but it’s not returning the expected results. Should I place parentheses around the conditions to ensure they’re evaluated correctly? And do I need to worry about the order of operations between “AND” and “OR”?

I’ve heard that sometimes adding “AND” conditions can complicate the statement, so I’d love some clarity on how to effectively combine these conditions without getting confused. It would be really helpful to see a simple example that illustrates the correct usage of “OR” alongside other operators. Thank you!

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    2 Answers

    1. Okay, so you wanna do an “OR” in SQL? It’s actually pretty simple! Think of it like this: you wanna check if one condition is true or another condition is true. You use the “OR” keyword.

      Let me break it down a bit for you. If you have a table called users and you want to find users who are either from ‘New York’ or ‘Los Angeles’, you would write something like this:

      SELECT * FROM users WHERE city = 'New York' OR city = 'Los Angeles';

      So, you’re just saying “give me all the users where the city is either New York OR Los Angeles.” Easy peasy!

      And if you have more conditions, you can keep adding them with the same “OR”. Like:

      SELECT * FROM users WHERE city = 'New York' OR city = 'Los Angeles' OR age > 25;

      This one says “give me users from New York, Los Angeles, or users older than 25.” Cool, right?

      Just remember: if you use “AND”, it means both conditions need to be true. But with “OR”, only one condition needs to be true for it to work. So, always think about what you really want to get!

      Happy coding!


    2. To perform a logical OR operation in SQL, you can use the `OR` operator in your `WHERE` clause. This operator allows you to combine multiple conditions, and if any of the conditions return true, the overall query will return the matching records. For instance, if you want to retrieve records from a `users` table where either the `age` is greater than 30 or the `city` is ‘New York’, your query would look like this:

      “`sql
      SELECT * FROM users
      WHERE age > 30 OR city = ‘New York’;
      “`

      This query effectively filters the dataset based on the specified criteria. Additionally, when working with more complex conditions, it’s advisable to use parentheses to group conditions and clarify the order of evaluation. For example, if you need to check if the users are either from ‘New York’ and older than 30 or from ‘Los Angeles’, you would use parentheses:

      “`sql
      SELECT * FROM users
      WHERE (city = ‘New York’ AND age > 30) OR city = ‘Los Angeles’;
      “`

      This structure helps maintain clarity and ensures that the query performs as intended.

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