knex/knex.js

// Knex.js  0.6.20
// --------------

//     (c) 2014 Tim Griesser
//     Knex may be freely distributed under the MIT license.
//     For details and documentation:
//     http://knexjs.org

// The "Knex" object we're exporting is just a passthrough to `Knex.initialize`.
function Knex() {
  return Knex.initialize.apply(null, arguments);
}

// Run a "raw" query, though we can't do anything with it other than put
// it in a query statement.
Knex.raw = function(sql, bindings) {
  return new Raw(sql, bindings);
};

// Require the main constructors necessary for a `Knex` instance,
// each of which are injected with the current instance, so they maintain
// the correct client reference & grammar.
var Raw = require('./lib/raw');

// Doing it this way makes it easier to build for browserify.
var mysql = function() { return require('./lib/dialects/mysql'); };
var mysql2 = function() { return require('./lib/dialects/mysql2'); };
var maria = function() { return require('./lib/dialects/maria'); };
var pg = function() { return require('./lib/dialects/postgres'); };
var sqlite3 = function() { return require('./lib/dialects/sqlite3'); };
var websql = function() { return require('./lib/dialects/websql'); };

// The client names we'll allow in the `{name: lib}` pairing.
var Clients = Knex.Clients = {
  'mysql'      : mysql,
  'mysql2'     : mysql2,
  'maria'      : maria,
  'mariadb'    : maria,
  'mariasql'   : maria,
  'pg'         : pg,
  'postgres'   : pg,
  'postgresql' : pg,
  'sqlite'     : sqlite3,
  'sqlite3'    : sqlite3,
  'websql'     : websql
};

// Require lodash.
var _ = require('lodash');
var Promise = require('./lib/promise');

// Each of the methods which may be statically chained from knex.
var QueryInterface   = require('./lib/query/methods');
var SchemaInterface  = require('./lib/schema/methods');
var MigrateInterface = require('./lib/migrate/methods');

// Create a new "knex" instance with the appropriate configured client.
Knex.initialize = function(config) {
  var Dialect, client;
  var EventEmitter = require('events').EventEmitter;

  // The object we're potentially using to kick off an
  // initial chain. It is assumed that `knex` isn't a
  // constructor, so we have no reference to 'this' just
  // in case it's called with `new`.
  function knex(tableName) {
    var qb = new client.QueryBuilder;
    if (config.__transactor__) qb.transacting(config.__transactor__);
    return tableName ? qb.table(tableName) : qb;
  }

  // Hook up the "knex" object as an EventEmitter.
  var ee = new EventEmitter();
  for (var key in ee) {
    knex[key] = ee[key];
  }

  // The `__knex__` is used if you need to duck-type check whether this
  // is a knex builder, without a full on `instanceof` check.
  knex.VERSION = knex.__knex__  = '0.6.20';
  knex.raw = function(sql, bindings) {
    var raw = new client.Raw(sql, bindings);
    if (config.__transactor__) raw.transacting(config.__transactor__);
    return raw;
  };

  // Runs a new transaction, taking a container and returning a promise
  // for when the transaction is resolved.
  knex.transaction = function(container) {
    return new client.Transaction(container);
  };

  // Convenience method for tearing down the pool.
  knex.destroy = function (callback) {
    var pool = this.client.pool;
    var promise = new Promise(function(resolver, rejecter) {
      if (!pool) resolver();
      pool.destroy(function(err) {
        if (err) return rejecter(err);
        resolver();
      });
    });
    // Allow either a callback or promise interface for destruction.
    if (_.isFunction(callback)) {
      promise.exec(callback);
    } else {
      return promise;
    }
  };

  if (config.__client__) {
    client = config.__client__;
  } else {
    // Build the "client"
    var clientName = config.client;
    if (!Clients[clientName]) {
      throw new Error(clientName + ' is not a valid Knex client, did you misspell it?');
    }
    knex.toString = function() {
      return '[object Knex:' + clientName + ']';
    };
    Dialect = Clients[clientName]();
    client  = new Dialect(config);

    // Passthrough all "start" and "query" events to the knex object.
    client.on('start', function(obj) {
      knex.emit('start', obj);
    });
    client.on('query', function(obj) {
      knex.emit('query', obj);
    });
  }

  // Allow chaining methods from the root object, before
  // any other information is specified.
  _.each(QueryInterface, function(method) {
    knex[method] = function() {
      var builder = knex();
      return builder[method].apply(builder, arguments);
    };
  });
  knex.client = client;

  // Namespaces for additional library components.
  var schema  = knex.schema  = {};
  var migrate = knex.migrate = {};

  // Attach each of the `Schema` "interface" methods directly onto to `knex.schema` namespace, e.g.:
  // `knex.schema.table('tableName', function() {...`
  // `knex.schema.createTable('tableName', function() {...`
  // `knex.schema.dropTableIfExists('tableName');`
  _.each(SchemaInterface, function(key) {
    schema[key] = function() {
      if (!client.SchemaBuilder) client.initSchema();
      var builder = new client.SchemaBuilder();
      if (config.__transactor__) builder.transacting(config.__transactor__);
      return builder[key].apply(builder, arguments);
    };
  });

  // Attach each of the `Migrator` "interface" methods directly onto to `knex.migrate` namespace, e.g.:
  // knex.migrate.latest().then(...
  // knex.migrate.currentVersion(...
  _.each(MigrateInterface, function(method) {
    migrate[method] = function() {
      if (!client.Migrator) client.initMigrator();
      var migrator = new client.Migrator(knex);
      return migrator[method].apply(migrator, arguments);
    };
  });

  // Add a few additional misc utils.
  knex.utils = _.extend({}, require('./lib/utils'));

  return knex;
};

module.exports = Knex;