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Database Schema

Campus Connect uses MongoDB with Mongoose to store user data, channels, and messages. The structure was designed to separate concerns, allow for scalability, and support real-time messaging.

All documents are stored in three main collections:

  • users
  • channels
  • messages

This structure ensures that channels remain lightweight and that messages can be created, queried, and updated efficiently.

User Schema – users Collection
users.schema.ts
{
    _id: string,
    email: string,
    username: string,
    password: string, // Hashed
    campus: string,

    // Social Graph
    friends: string[],
    friendRequests: string[],
    sentFriendRequests: string[],
    blockedUsers: string[],

    createdAt: Date,
    updatedAt: Date
}
  • Users can send and receive friend requests, block others, and maintain a list of confirmed friends.
    • (not all features have been implmented on the front end yet)
  • All relationships are stored as array of user IDs (strings), making it easier to join or populate as needed.
  • Passwords are hashed before storage (using bcrypt).
Channel Schema – channels Collection
channel.schema.ts
{
    _id: string,
    type: 'DM' | 'GROUP',
    name?: string,
    participants: string[], // User IDs

    createdAt: Date,
    updatedAt: Date
}
  • A channel can be either a DM (direct message between two users) or a GROUP (future support).
  • The list of participants is stored as an array of user IDs.
  • Channels are deliberately lightweight – no messages are embedded.
Message Schema – messages Collection
message.schema.ts
{
    _id: string,
    channelId: string,
    senderId: string,
    senderName?: string,
    content: string,
    edited: boolean,

    createdAt: Date,
    updatedAt: Date
}
  • Messages are stored in a separate collection
  • Messages reference both the channelId and senderId.
  • When a message is edited, the edited flag is set to true for transparency.
MongoDB Entity Relationship 
erDiagram
    USER ||--o{ CHANNEL : participates_in
    USER ||--o{ MESSAGE : sends
    CHANNEL ||--o{ MESSAGE : contains

    USER {
        string _id
        string email
        string username
        string password
        string campus
        string[] friends
        string[] friendRequests
        string[] sentFriendRequests
        string[] blockedUsers
    }

    CHANNEL {
        string _id
        string type
        string name
        string[] participants
    }

    MESSAGE {
        string _id
        string channelId
        string senderId
        string content
        boolean edited
        date createdAt
    }