knex/lib/raw.js

'use strict';

// Raw
// -------
var _            = require('lodash')
var inherits     = require('inherits')
var EventEmitter = require('events').EventEmitter
var assign       = require('lodash/object/assign');

function Raw(client) {
  this.sql      = ''
  this.bindings = []
  this.client   = client
}
inherits(Raw, EventEmitter)

assign(Raw.prototype, {

  set: function(sql, bindings) {
    if (sql && sql.toSQL) {
      var output = sql.toSQL()
      sql = output.sql
      bindings = output.bindings
    }
    this.sql = sql + ''
    this.bindings = ([]).concat(bindings === undefined ? [] : bindings)
    this.interpolateBindings()
    this._debug       = void 0
    return this
  },

  // Wraps the current sql with `before` and `after`.
  wrap: function(before, after) {
    this.sql = before + this.sql + after
    return this
  },

  // Calls `toString` on the Knex object.
  toString: function() {
    return this.toQuery()
  },

  // Ensure all Raw / builder bindings are mixed-in to the ? placeholders
  // as appropriate.
  interpolateBindings: function() {
    var replacements = []
    this.bindings = _.reduce(this.bindings, function(accum, param, index) {
      var innerBindings = [param]
      if (param && param.toSQL) {
        var result    = this.splicer(param, index)
        innerBindings = result.bindings
        replacements.push(result.replacer)
      }
      return accum.concat(innerBindings)
    }, [], this)

    // we run this in reverse order, because ? concats earlier in the
    // query string will disrupt indices for later ones
    this.sql = _.reduce(replacements.reverse(), function(accum, fn) {
      return fn(accum)
    }, this.sql.split('?')).join('?')
  },

  // Returns a replacer function that splices into the i'th
  // ? in the sql string the inner raw's sql,
  // and the bindings associated with it
  splicer: function(raw, i) {
    var obj = raw.toSQL()

    // the replacer function assumes that the sql has been
    // already sql.split('?') and will be arr.join('?')
    var replacer = function(arr) {
      arr[i] = arr[i] + obj.sql + arr[i + 1]
      arr.splice(i + 1, 1)
      return arr
    }

    return {
      replacer: replacer,
      bindings: obj.bindings
    }
  },

  // Returns the raw sql for the query.
  toSQL: function() {
    return {
      sql: this.sql,
      method: 'raw',
      bindings: this.bindings
    }
  }

})

// Allow the `Raw` object to be utilized with full access to the relevant
// promise API.
require('./interface')(Raw)

module.exports = Raw