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Social Network Database Schema

The relational backbone of a social app. Users follow other users (a self-referencing many-to-many), publish posts, and engage through likes and comments. It is a compact but complete model you can grow into messaging, notifications, or media attachments.

Open in editor → 5 tables · MySQL DDL

Tables in this schema

usersfollowspostslikescomments

Schema (SQL)

MySQL-dialect DDL. Open it in the editor for a visual ER diagram you can edit, or copy the SQL straight into your project.

CREATE TABLE users (
  id INT PRIMARY KEY AUTO_INCREMENT,
  username VARCHAR(50) NOT NULL UNIQUE,
  email VARCHAR(254) NOT NULL UNIQUE,
  bio VARCHAR(280),
  created_at DATETIME NOT NULL
);

CREATE TABLE follows (
  follower_id INT NOT NULL,
  followee_id INT NOT NULL,
  created_at DATETIME NOT NULL,
  PRIMARY KEY (follower_id, followee_id),
  FOREIGN KEY (follower_id) REFERENCES users(id),
  FOREIGN KEY (followee_id) REFERENCES users(id)
);

CREATE TABLE posts (
  id INT PRIMARY KEY AUTO_INCREMENT,
  author_id INT NOT NULL,
  body TEXT NOT NULL,
  created_at DATETIME NOT NULL,
  FOREIGN KEY (author_id) REFERENCES users(id)
);

CREATE TABLE likes (
  user_id INT NOT NULL,
  post_id INT NOT NULL,
  created_at DATETIME NOT NULL,
  PRIMARY KEY (user_id, post_id),
  FOREIGN KEY (user_id) REFERENCES users(id),
  FOREIGN KEY (post_id) REFERENCES posts(id)
);

CREATE TABLE comments (
  id INT PRIMARY KEY AUTO_INCREMENT,
  post_id INT NOT NULL,
  author_id INT NOT NULL,
  body VARCHAR(1000) NOT NULL,
  created_at DATETIME NOT NULL,
  FOREIGN KEY (post_id) REFERENCES posts(id),
  FOREIGN KEY (author_id) REFERENCES users(id)
);

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