Initial SQL structure for new comments database.

CREATE TABLE comments (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    user_id INT NOT NULL,

    target_id INT NOT NULL,

    content TEXT NOT NULL,

    content_html TEXT NOT NULL,

    created_at DATETIME NOT NULL,

    rating INT NOT NULL DEFAULT 0,

    deleted ENUM('Y', 'N') NOT NULL DEFAULT 'N',

    FOREIGN KEY (user_id) REFERENCES users (id),

    FOREIGN KEY (target_id) REFERENCES targets (id)

);

CREATE TABLE users (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    name VARCHAR(255) NOT NULL,

    email VARCHAR(255) NOT NULL, -- (from subscriptions)

    email_hash VARCHAR(255) NOT NULL,

    moderator ENUM('Y', 'N') NOT NULL DEFAULT 'N'

);

CREATE TABLE targets (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    sdk VARCHAR(255) NOT NULL,

    version VARCHAR(255) NOT NULL,

    type ENUM('class', 'guide', 'video') NOT NULL DEFAULT 'class',

    cls VARCHAR(255) NOT NULL,    -- "Ext.draw.Sprite"

    member VARCHAR(255) NOT NULL  -- "method-setAttributes"

);

CREATE TABLE votes (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    user_id INT NOT NULL,

    comment_id INT NOT NULL,

    value INT NOT NULL, -- +1 or -1

    created_at DATETIME NOT NULL, -- (no data available for now)

    FOREIGN KEY (user_id) REFERENCES users (id),

    FOREIGN KEY (comment_id) REFERENCES comments (id)

);

CREATE TABLE updates (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    user_id INT NOT NULL,

    comment_id INT NOT NULL,

    action ENUM('update', 'delete') DEFAULT 'update',

    created_at DATETIME NOT NULL,

    FOREIGN KEY (user_id) REFERENCES users (id),

    FOREIGN KEY (comment_id) REFERENCES comments (id)

);

CREATE TABLE subscriptions (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    user_id INT NOT NULL,

    target_id INT NOT NULL,

    created_at DATETIME NOT NULL, -- (no data available for now)

    FOREIGN KEY (user_id) REFERENCES users (id),

    FOREIGN KEY (target_id) REFERENCES targets (id)

);

CREATE TABLE read_comments (

    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

    user_id INT NOT NULL,

    comment_id INT NOT NULL,

    created_at DATETIME NOT NULL, -- (no data available for now)

    FOREIGN KEY (user_id) REFERENCES users (id),

    FOREIGN KEY (comment_id) REFERENCES comments (id)

);