Distinct records

- [Instructor] In this movie, we will learn…how we could end up with duplicate records…from a joined query, and now to handle it when you do.…When we use the joins method, the SQL that it writes…is an SQL inner join.…And that's a particular type of join in SQL.…We're going to talk more about another type in a moment.…But for now, let's talk about some of the characteristics…of using an inner join.…As we already saw, it makes a related table…available in a query.…It also has two other characteristics.…One is that it can create duplicate entries,…and you may have noticed that in the last movie.…

We'll talk more about that in just a moment.…It's primarily a concern when we have a one to many…relationship, or a has_many relationship in Rails.…And the second characteristic is that it includes…only records which have the relationship.…Records which do not have the relationship…will be omitted from the results.…We're going to talk about this more in the following movie.…For now I want us to focus on that third bullet point,…