How to select only specific attributes from a model?

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傲寒
傲寒 2021-01-02 05:20

I want to select only specific attributes from a model(id,name).

The SQL-command can be for example:

SELECT id,name,username FROM Users

Do you know h

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  •  青春惊慌失措
    2021-01-02 05:51

    There's a :select option on find methods. This allows you to do:

    User.find(:all, :select => 'id, name, username')
    

    The returned objects will be User instances with those attributes available.

    Or if you really want just the values without wrapping them us as User instances. You can add a method to User to return them.

    def self.get_ids_and_names
      self.connection.select_all("select id, name, username from users")
    end
    

    which will return an array of hashes mapping column name to the value for that row. E.g. [{'id' => 1, 'name' => 'user1', 'username' => 'username1'}, ... ]

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