Issue with conception | Together Java | Page 1

opal zinc Dec 8, 2025, 8:41 PM

#

Hello guys
I'm training to be an application designer and developer. I have to present a project to the jury. I'm learning Kotlin on the side, but I'm having trouble with the data design model. I have many-to-many relationships, which makes things vague and complex. Can you help me?
My project is to create a Discord-style app, or at least a simple messaging app. I have to present this project to the jury for 40 minutes.

CREATE TABLE user_account(
   account_id INT,
   account_name VARCHAR(20) NOT NULL,
   account_tag VARCHAR(4) NOT NULL,
   account_email VARCHAR(100) NOT NULL,
   password VARCHAR(60) NOT NULL,
   avatar_path VARCHAR(500) NOT NULL,
   PRIMARY KEY(account_id),
   UNIQUE(account_tag),
   UNIQUE(account_email)
);

CREATE TABLE channel(
   channel_id INT,
   PRIMARY KEY(channel_id)
);

CREATE TABLE role(
   role_id INT,
   label VARCHAR(50) NOT NULL,
   PRIMARY KEY(role_id),
   UNIQUE(label)
);

CREATE TABLE message(
   message_id INT,
   message_date DATETIME NOT NULL,
   message_content VARCHAR(2000) NOT NULL,
   channel_id INT NOT NULL,
   account_id INT NOT NULL,
   PRIMARY KEY(message_id),
   FOREIGN KEY(channel_id) REFERENCES channel(channel_id),
   FOREIGN KEY(account_id) REFERENCES user_account(account_id)
);

CREATE TABLE linkedTo(
   account_id INT,
   channel_id INT,
   PRIMARY KEY(account_id, channel_id),
   FOREIGN KEY(account_id) REFERENCES user_account(account_id),
   FOREIGN KEY(channel_id) REFERENCES channel(channel_id)
);

CREATE TABLE assignedTo(
   account_id INT,
   role_id INT,
   PRIMARY KEY(account_id, role_id),
   FOREIGN KEY(account_id) REFERENCES user_account(account_id),
   FOREIGN KEY(role_id) REFERENCES role(role_id)
);