问题
Regarding my last attempted answer, I could achieve what I wanted. Once the app is working I noticed something is different: only the person that created the message and sends a message was only showing. If I reply, I do not see the reply and I know the problem.
My Message model has tables: [:id, :user_id, :to, :body, ...]
:user_id would be similar to from as that is used to determine who created the message.
User 1 would be Client and User 2 is Student. Student sends a message to Client. Only my client side the code is as this:
#Controller Index:
@messages = Message.where(to: current_user.id) # My replies are not included here
.order(user_id: :asc, created_at: :desc)
.select('distinct on (user_id) *')
I'm saying give me all messages that's addressed to me (:to) an id of 1.
I won't see my reply because of the :to column.
My (client) reply looks like this:
to: #student id
user_id: #client id
And student message:
to: #client id
user_id: #student id
So because the to now point to an id, let's say 2 I wont see the reply. I may need to change up the model but if you see an easy way, please let me know.
Edit:
Answer that works great:
@messages = Message.where(to: current_user.id).or(Message.where(user_id: current_user.id))
.order(connection: :desc, created_at: :desc)
.select('distinct on (connection) *')
回答1:
Since you are using Rails 5, you can take advantage of it's or method:
Message.where(to: current_user.id).or(
Message.where(user_id: current_user.id)
).order(connection: :desc, created_at: :desc)
.select('distinct on (connection) *')
来源：https://stackoverflow.com/questions/37879169/show-last-message-in-a-message-array