db.js

const Pgp = require('pg-promise')
    , config = require('./config')

const pgp = new Pgp(options)
    , db = pgp(config.postgresUrl)

module.exports = function(x, ...args) {
  if (!Array.isArray(x) || !Array.isArray(x.raw))
    throw new Error('db queries must be done as template strings')

  let add = 0
  return db.query(x.reduce((acc, x, i) =>
    acc += (
      Array.isArray(args[i - 1])
        ? args[i - 1].map((x) =>
          Array.isArray(x)
            ? '(' + x.map(x => '$(w.' + (-1 + i + add++) + ')').join(',') + ')'
            : '$(w.' + (-1 + i + add++) + ')'
        ).join(',')
        : ('$(w.' + (-1 + i) + ')')
      )
    + x
  ), { w: args.flat(Infinity) })
}