TypeORM: What is the difference between getRawMany() and getMany()?

I have this code:

  let otherParticipants = await chatRoomParticipantRepo
    .createQueryBuilder("chatRoomParticipant")
    .leftJoinAndSelect("chatRoomParticipant.user", "user")
    .select("user.connectionId")
    .where("chatRoomParticipant.chatRoomId = :chatRoomId AND chatRoomParticipant.userId != :userId")
    .setParameters({ chatRoomId: chatRoomId, userId: userId })
    .getRawMany();

Which gives me this result:

[{user_connectionId: 's7p7bUbzt0wudKcxAAAD'}]

If I do it with getMany() it gives me empty array:

[]

I am trying to get the ID from user which connected to chatRoomParticipant, but I cannot do it with this code:

  let otherParticipants = await chatRoomParticipantRepo
    .createQueryBuilder("chatRoomParticipant")
    .leftJoinAndSelect("chatRoomParticipant.user", "user")
    .select("user.connectionId")
    .where("chatRoomParticipant.chatRoomId = :chatRoomId AND chatRoomParticipant.userId != :userId")
    .setParameters({ chatRoomId: chatRoomId, userId: userId })
    .getMany(); <-- This gives nothing

Why is this happening? I thought getRawMany() is just for SUM, COUNT, etc. In this case I am trying to get the ID which should work with getMany() as well?

In your case, you should use getRawMany() because you want to select some specified fields of your entity,getMany() it returns array of entities concern