Rails filtering array of objects by attribute value

Question

So I perform a query to the db and I have a complete array of objects    attachments   Job find 1  attachments   Now that I have an array of objects I don t want to perform another db query  but I would like to filter the array based on the Attachment object s file type so that I can have a list of attachments where the file type is  logo  and then another list of attachments where the file type is  image   Something like this    logos     attachments where  file type        logo    images    attachments where  file type        image     But in memory instead of a db query

User · Answer

I d go about this slightly differently  Structure your query to retrieve only what you need and split from there   So make your query the following                                    vv or Job find 1  vv attachments   Attachment where job id   job id  file type    logo    image       or  Job includes  attachments  where id  your job id  attachments    file type    logo    image        And then partition the data    logos   images   attachments partition    attachment  attachment file type     logo      That will get the data you re after in a neat and efficient manner

User · Answer

have you tried eager loading     attachments   Job includes  attachments  find 1  attachments

User · Answer

If your attachments are    attachments   Job find 1  attachments   This will be array of attachment objects  Use select method to filter based on file type    logos    attachments select    attachment  attachment file type     logo     images    attachments select    attachment  attachment file type     image      This will not trigger any db query

User · Answer

You can filter using where  Job includes  attachments  where file type    logo    image

User · Answer

Try    This is fine     logos    attachments select    attachment  attachment file type     logo     images    attachments select    attachment  attachment file type     image      but for performance wise you don t need to iterate  attachments twice     logos    images           attachments each do  attachment     logos  lt  lt  attachment if attachment file type     logo     images  lt  lt  attachment if attachment file type     image  end

[ruby-on-rails] Rails filtering array of objects by attribute value

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