How do I use joins in ActiveRecord?

How do I use joins in ActiveRecord?

You can use the joins method to combine records from different tables. For example, Post.joins(:comments) will return all posts that have comments.

Can you give me an example with conditions?

Sure! You can add conditions like this: Post.joins(:comments).where(comments: { approved: true }) to get only posts with approved comments.

What if I want to include the associated records in the result?

In that case, you should use includes instead of joins. For example, Post.includes(:comments) will load posts along with their comments.

Is there a way to use both joins and includes?

Yes, you can chain them! For example, Post.joins(:comments).includes(:author) will join comments and include authors.