db.js

const spicedPg = require('spiced-pg');

const db = spicedPg(
    process.env.DATABASE_URL ||
        'postgres:postgres:postgres@localhost:5432/imageboard'
);

exports.getImage = id => {
    const q = `
        SELECT * FROM images
        WHERE id = $1
        ORDER BY id DESC`;
    return db.query(q, [id]);
};

exports.getImages = lastImgId => {
    const q = `
        SELECT id, url, title, description, (
            SELECT id FROM images
            ORDER BY id ASC
            LIMIT 1
        ) AS "lowestId" FROM images 
        ${lastImgId == 0 ? '' : 'WHERE id < $1'}
        ORDER BY id DESC
        LIMIT 12`;
    return lastImgId == 0 ? db.query(q) : db.query(q, [lastImgId]);
};

exports.addImage = (title, description, username, url) => {
    const q = `
        INSERT INTO images (title, description, username, url)
        VALUES ($1, $2, $3, $4)
        RETURNING *`;
    return db.query(q, [title, description, username, url]);
};

exports.addComment = (id, username, comment) => {
    const q = `
        INSERT INTO comments (img_id, username, comment)
        VALUES ($1, $2, $3)
        RETURNING *`;
    return db.query(q, [id, username, comment]);
};

exports.getComments = id => {
    const q = `
        SELECT * FROM comments
        WHERE img_id = $1
        ORDER BY id DESC`;
    return db.query(q, [id]);
};