How to use the knex.initialize function in knex

var crypto = require('crypto');
var Knex = require('knex');
var twilio = require('twilio');
var client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);

var knex = Knex.initialize({
  client: 'pg',
  connection: process.env.DATABASE_URL
});

// Finds reminders for cases happening tomorrow
var findReminders = function() {
  return knex('reminders')
    .where('sent', false)
    .join('cases', 'reminders.case_id', '=', 'cases.id')
    .where('cases.date', 'tomorrow')
    .select();
};

findReminders().exec(function(err, results) {
  if (results.length === 0) {
    console.log('No reminders to send out today.');

var config = require('../config');
var Knex = require('knex');

var knex = Knex.initialize({
    client: 'postgres',
    connection : config.database.postgres
});
// add fields
knex.schema.hasTable('blob').then(function(exists) {
    if (!exists) 
        knex.schema
        .createTable('blob', function (table) {
            table.string('id').primary();
            table.string('address');
            table.string('auth_secret');
            table.integer('revision');
            table.binary('data');
            table.string('username');
            table.boolean('email_verified');
            table.string('email');

// Creates the reminders table.
var Knex = require('knex');

var knex = Knex.initialize({
  client: 'pg',
  connection: process.env.HEROKU_POSTGRESQL_NAVY_URL
});

var createTable = function() {
  return knex.schema.createTable('queued', function(table) {
    table.increments('queued_id').primary();
    table.dateTime('created_at');
    table.string('citation_id', 100);
    table.string('phone', 100);
    table.boolean('sent', 100);
  });
};

var close = function() {
  return knex.client.pool.destroy();

var config = require('../config');
var Knex = require('knex');

var knex = Knex.initialize({
    client: 'mysql',
    connection : config.database.mysql
});
// add fields
knex.schema.hasTable('blob').then(function(exists) {
    if (!exists) 
        knex.schema
        .createTable('blob', function (table) {
            table.string('id').primary();
            table.string('address');
            table.string('auth_secret');
            table.integer('revision');
            table.binary('data');
            table.string('username');
            table.boolean('email_verified');
            table.string('email');

var reporter = require('../lib/reporter');
var EC = require('../emailcampaign');
var config = require('../config');
var QL = require('queuelib');
var Knex = require('knex');

var assert = require('assert');

var user_a = {"username":"Seelan","auth_secret":"FFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0A","id":"fffd0a0affff0a0affff0a0affff0a0affff0a0affff0a0affff0a0affff0a0a","data":"Zm9v","address":"rwUNHL9AdSupre4tGb7NXZpRS1ift5sR7W","email":"bob@bob.com","hostlink":"http://localhost:8080/activate","encrypted_secret":"r5nUDJLNQfWERYFm1sUSxxhate8r1q","encrypted_blobdecrypt_key":"asdfasdfasdf"};
var user_b = {"username":"Palleen","auth_secret":"FFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0AFFFF0A0A","id":"ffef0a0affff0a0affff0a0affff0a0affff0a0affff0a0affff0a0affff0a0a","data":"Zm9v","address":"rJdWmijaRPvHZ9M9PNAqhs88nTnYivTZtq","email":"rook2pawn@gmail.com","hostlink":"http://localhost:8080/activate","encrypted_secret":"r5nUDJLNQfWERYFm1sUSxxhate8r1q","encrypted_blobdecrypt_key":"asdfasdfasdf"};

var db = Knex.initialize({
    client: 'postgres',
    connection : config.database.postgres
});
var ec = new EC(db,config)
var DAY = 1000*60*60*24;

var donecount = 0;

var actionhistory = [];
var probe = function(data) {
    switch (data.action) {
        case 'check':
        reporter.log("Time till next check:"+ (data.timetill/(1000*60)) + " minutes")
        break;
        default :
        reporter.log("Unspecified case",data)

var DB = function(config) {
  var self  = this;
  self.knex = Knex.initialize({
      client     : 'postgres',
      connection : config
  });

 /**
  * migrate
  * run latest db migrations
  */
  self.migrate = function () {
    return self.knex.migrate.latest()
    .spread(function(batchNo, list) {
      if (list.length === 0) {
        log.info('Migration: up to date');
      } else {
        log.info('Migration: batch ' + batchNo + ' run: ' + list.length + ' migrations \n' + list.join('\n'));
      }

Initializer.add('startup', 'stex.db', ['stex.config', 'stex.logging', 'stex.newrelic'], function(stex) {
  var Knex = require('knex');
  var config = stex.conf.get("db");
  config.connection = _.extend(config.connection, {
    stringifyObjects: true
  });
  stex.db  = Knex.initialize(config);

  stex.db.on("query", function(query) {
    log.info("query", {
      sql: query.sql
    })
  });

  global.db = stex.db;
});

var fs = require('fs');
var csv = require('csv');
var _ = require('underscore');
var Knex = require('knex');
var Promise = require('bluebird');

var knex = Knex.initialize({
  client: 'pg',
  connection: process.env.DATABASE_URL
});

var createTable = function() {
  return knex.schema.createTable('cases', function(t) {
    t.increments('id').primary();
    t.string('defendant', 100);
    t.string('room', 100);
    t.string('date', 100);
    t.string('time', 100);
    t.string('citation', 100);
    t.string('violation_code', 100);
    t.string('violation_desc', 100);
  });
}

var DB = function(config) {
  var self = this;
  self.knex = Knex.initialize({
      client     : 'postgres',
      connection : config
  });
  var bookshelf = require('bookshelf')(self.knex);

  //Define Bookshelf models
  var Ledger = bookshelf.Model.extend({
      tableName: 'ledgers',
      idAttribute: 'ledger_hash'
  });

  var Transaction = bookshelf.Model.extend({
      tableName: 'transactions',
      idAttribute: 'tx_hash'
  });

MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

var path = require('path');
var nconf = require('./config');

var conf = nconf.get('db');

conf.migrations = { directory: path.resolve(__dirname, '../migrations') };

var knex = require('knex').initialize(conf);
var bookshelf = require('bookshelf').initialize(knex);

exports.knex = knex;
exports.bookshelf = bookshelf;
exports.conf = conf;