<?php
$createTablesPg = array(
    "
        CREATE TABLE IF NOT EXISTS classes (
            id SERIAL PRIMARY KEY,
            name VARCHAR(50) NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        );
    ",

    "
        CREATE TABLE IF NOT EXISTS class_students (
            class_id INT NOT NULL,
            student_id INT NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            PRIMARY KEY (class_id, student_id)
        );
    ",

    "
        CREATE TABLE IF NOT EXISTS teacher_classes (
            teacher_id INT NOT NULL,
            class_id INT NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            PRIMARY KEY (teacher_id, class_id)
        );
    ",

    "
        CREATE TABLE IF NOT EXISTS event_class_bind (
            id SERIAL PRIMARY KEY,
            event_id INT NOT NULL,
            class_id INT NOT NULL
        );
    ",


);