如何对记录进行分组，然后根据列选择不同的记录

Question

I am trying to group some records by category and then select all distinct/unique records based on alias column. Here is as far as i got but its not working - it still brings non distinct records.

Location.where("calendar_account_id = ?", current_user.calendar_accounts.first).group(:id,:alias).order("alias ASC").distinct.group_by(&:category)

What am I doing wrong here?

Answer 1

Try this,

Location.select("DISTINCT(alias), *").where("calendar_account_id = ?", current_user.calendar_accounts.first).order("alias ASC").group_by(&:category)

or

Location.where("calendar_account_id = ?", current_user.calendar_accounts.first).group(:alias).order("alias ASC").group_by(&:category)