text: 
  // Builder
  // -------
  import assert from 'assert';
  import inherits from 'inherits';
  import { EventEmitter } from 'events';
  
  import Raw from '../raw';
  import * as helpers from '../helpers';
  import JoinClause from './joinclause';
  import {
    assign, clone, each, isBoolean, isEmpty, isFunction, isNumber, isObject,
    isString, isUndefined, tail, toArray
  } from 'lodash';
  
  // Typically called from `knex.builder`,
  // start a new query building chain.
  function Builder(client) {
    this.client = client
    this.and = this;
    this._single = {};
    this._statements = [];
    this._method = 'select'
    this._debug = client.config && client.config.debug;
  
    // Internal flags used in the builder.
    this._joinFlag = 'inner';
    this._boolFlag = 'and';
    this._notFlag = false;
  }
  inherits(Builder, EventEmitter);
  
  assign(Builder.prototype, {
  
    toString() {
      return this.toQuery();
    },
  
    // Convert the current query "toSQL"
    toSQL(method, tz) {
      return this.client.queryCompiler(this).toSQL(method || this._method, tz);
    },
  
    // Create a shallow clone of the current query builder.
    clone() {
      const cloned = new this.constructor(this.client);
      cloned._method = this._method;
      cloned._single = clone(this._single);
      cloned._statements = clone(this._statements);
      cloned._debug = this._debug;
  
      // `_option` is assigned by the `Interface` mixin.
      if (!isUndefined(this._options)) {
        cloned._options = clone(this._options);
      }
  
      return cloned;
    },
  
    timeout(ms, {cancel} = {}) {
      if(isNumber(ms) && ms > 0) {
        this._timeout = ms;
        if (cancel) {
          this.client.assertCanCancelQuery();
          this._cancelOnTimeout = true;
        }
      }
      return this;
    },
  
    // Select
    // ------
  
    // Adds a column or columns to the list of "columns"
    // being selected on the query.
    columns(column) {
      if (!column) return this;
      this._statements.push({
        grouping: 'columns',
        value: helpers.normalizeArr.apply(null, arguments)
      });
      return this;
    },
  
    // Allow for a sub-select to be explicitly aliased as a column,
    // without needing to compile the query in a where.
    as(column) {
      this._single.as = column;
      return this;
    },
  
    // Prepends the `schemaName` on `tableName` defined by `.table` and `.join`.
    withSchema(schemaName) {
      this._single.schema = schemaName;
      return this;
    },
  
    // Sets the `tableName` on the query.
    // Alias to "from" for select and "into" for insert statements
    // e.g. builder.insert({a: value}).into('tableName')
    table(tableName) {
      this._single.table = tableName;
      return this;
    },
  
    // Adds a `distinct` clause to the query.
    distinct() {
      this._statements.push({
        grouping: 'columns',
        value: helpers.normalizeArr.apply(null, arguments),
        distinct: true
      });
      return this;
    },
  
    // Adds a join clause to the query, allowing for advanced joins
    // with an anonymous function as the second argument.
    // function(table, first, operator, second)
    join(table, first) {
      let join;
      const { schema } = this._single;
      const joinType = this._joinType();
      if (typeof first === 'function') {
        join = new JoinClause(table, joinType, schema);
        first.call(join, join);
      } else if (joinType === 'raw') {
        join = new JoinClause(this.client.raw(table, first), 'raw');
      } else {
        join = new JoinClause(table, joinType, schema);
        if (arguments.length > 1) {
          join.on.apply(join, toArray(arguments).slice(1));
        }
      }
      this._statements.push(join);
      return this;
    },
  
    // JOIN blocks:
    innerJoin() {
      return this._joinType('inner').join.apply(this, arguments);
    },
    leftJoin() {
      return this._joinType('left').join.apply(this, arguments);
    },
    leftOuterJoin() {
      return this._joinType('left outer').join.apply(this, arguments);
    },
    rightJoin() {
      return this._joinType('right').join.apply(this, arguments);
    },
    rightOuterJoin() {
      return this._joinType('right outer').join.apply(this, arguments);
    },
    outerJoin() {
      return this._joinType('outer').join.apply(this, arguments);
    },
    fullOuterJoin() {
      return this._joinType('full outer').join.apply(this, arguments);
    },
    crossJoin() {
      return this._joinType('cross').join.apply(this, arguments);
    },
    joinRaw() {
      return this._joinType('raw').join.apply(this, arguments);
    },
  
    // The where function can be used in several ways:
    // The most basic is `where(key, value)`, which expands to
    // where key = value.
    where(column, operator, value) {
  
      // Support "where true || where false"
      if (column === false || column === true) {
        return this.where(1, '=', column ? 1 : 0)
      }
  
      // Check if the column is a function, in which case it's
      // a where statement wrapped in parens.
      if (typeof column === 'function') {
        return this.whereWrapped(column);
      }
  
      // Allow a raw statement to be passed along to the query.
      if (column instanceof Raw && arguments.length === 1) return this.whereRaw(column);
  
      // Allows `where({id: 2})` syntax.
      if (isObject(column) && !(column instanceof Raw)) return this._objectWhere(column);
  
      // Enable the where('key', value) syntax, only when there
      // are explicitly two arguments passed, so it's not possible to
      // do where('key', '!=') and have that turn into where key != null
      if (arguments.length === 2) {
        value = operator;
        operator = '=';
  
        // If the value is null, and it's a two argument query,
        // we assume we're going for a `whereNull`.
        if (value === null) {
          return this.whereNull(column);
        }
      }
  
      // lower case the operator for comparison purposes
      const checkOperator = (`${operator}`).toLowerCase().trim();
  
      // If there are 3 arguments, check whether 'in' is one of them.
      if (arguments.length === 3) {
        if (checkOperator === 'in' || checkOperator === 'not in') {
          return this._not(checkOperator === 'not in').whereIn(arguments[0], arguments[2]);
        }
        if (checkOperator === 'between' || checkOperator === 'not between') {
          return this._not(checkOperator === 'not between').whereBetween(arguments[0], arguments[2]);
        }
      }
  
      // If the value is still null, check whether they're meaning
      // where value is null
      if (value === null) {
  
        // Check for .where(key, 'is', null) or .where(key, 'is not', 'null');
        if (checkOperator === 'is' || checkOperator === 'is not') {
          return this._not(checkOperator === 'is not').whereNull(column);
        }
      }
  
      // Push onto the where statement stack.
      this._statements.push({
        grouping: 'where',
        type: 'whereBasic',
        column,
        operator,
        value,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
    // Adds an `or where` clause to the query.
    orWhere: function orWhere() {
      this._bool('or');
      const obj = arguments[0];
      if(isObject(obj) && !isFunction(obj) && !(obj instanceof Raw)) {
        return this.whereWrapped(function() {
          for(const key in obj) {
            this.andWhere(key, obj[key]);
          }
        });
      }
      return this.where.apply(this, arguments);
    },
  
    // Adds an `not where` clause to the query.
    whereNot() {
      return this._not(true).where.apply(this, arguments);
    },
  
    // Adds an `or not where` clause to the query.
    orWhereNot() {
      return this._bool('or').whereNot.apply(this, arguments);
    },
  
    // Processes an object literal provided in a "where" clause.
    _objectWhere(obj) {
      const boolVal = this._bool();
      const notVal = this._not() ? 'Not' : '';
      for (const key in obj) {
        this[boolVal + 'Where' + notVal](key, obj[key]);
      }
      return this;
    },
  
    // Adds a raw `where` clause to the query.
    whereRaw(sql, bindings) {
      const raw = (sql instanceof Raw ? sql : this.client.raw(sql, bindings));
      this._statements.push({
        grouping: 'where',
        type: 'whereRaw',
        value: raw,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
  
    orWhereRaw(sql, bindings) {
      return this._bool('or').whereRaw(sql, bindings);
    },
  
    // Helper for compiling any advanced `where` queries.
    whereWrapped(callback) {
      this._statements.push({
        grouping: 'where',
        type: 'whereWrapped',
        value: callback,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
  
  
    // Helper for compiling any advanced `having` queries.
    havingWrapped(callback) {
      this._statements.push({
        grouping: 'having',
        type: 'whereWrapped',
        value: callback,
        bool: this._bool()
      });
      return this;
    },
  
    // Adds a `where exists` clause to the query.
    whereExists(callback) {
      this._statements.push({
        grouping: 'where',
        type: 'whereExists',
        value: callback,
        not: this._not(),
        bool: this._bool(),
      });
      return this;
    },
  
    // Adds an `or where exists` clause to the query.
    orWhereExists(callback) {
      return this._bool('or').whereExists(callback);
    },
  
    // Adds a `where not exists` clause to the query.
    whereNotExists(callback) {
      return this._not(true).whereExists(callback);
    },
  
    // Adds a `or where not exists` clause to the query.
    orWhereNotExists(callback) {
      return this._bool('or').whereNotExists(callback);
    },
  
    // Adds a `where in` clause to the query.
    whereIn(column, values) {
      if (Array.isArray(values) && isEmpty(values)) return this.where(this._not());
      this._statements.push({
        grouping: 'where',
        type: 'whereIn',
        column,
        value: values,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
  
    // Adds a `or where in` clause to the query.
    orWhereIn(column, values) {
      return this._bool('or').whereIn(column, values);
    },
  
    // Adds a `where not in` clause to the query.
    whereNotIn(column, values) {
      return this._not(true).whereIn(column, values);
    },
  
    // Adds a `or where not in` clause to the query.
    orWhereNotIn(column, values) {
      return this._bool('or')._not(true).whereIn(column, values);
    },
  
    // Adds a `where null` clause to the query.
    whereNull(column) {
      this._statements.push({
        grouping: 'where',
        type: 'whereNull',
        column,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
  
    // Adds a `or where null` clause to the query.
    orWhereNull(column) {
      return this._bool('or').whereNull(column);
    },
  
    // Adds a `where not null` clause to the query.
    whereNotNull(column) {
      return this._not(true).whereNull(column);
    },
  
    // Adds a `or where not null` clause to the query.
    orWhereNotNull(column) {
      return this._bool('or').whereNotNull(column);
    },
  
    // Adds a `where between` clause to the query.
    whereBetween(column, values) {
      assert(Array.isArray(values), 'The second argument to whereBetween must be an array.')
      assert(values.length === 2, 'You must specify 2 values for the whereBetween clause')
      this._statements.push({
        grouping: 'where',
        type: 'whereBetween',
        column,
        value: values,
        not: this._not(),
        bool: this._bool()
      });
      return this;
    },
  
    // Adds a `where not between` clause to the query.
    whereNotBetween(column, values) {
      return this._not(true).whereBetween(column, values);
    },
  
    // Adds a `or where between` clause to the query.
    orWhereBetween(column, values) {
      return this._bool('or').whereBetween(column, values);
    },
  
    // Adds a `or where not between` clause to the query.
    orWhereNotBetween(column, values) {
      return this._bool('or').whereNotBetween(column, values);
    },
  
    // Adds a `group by` clause to the query.
    groupBy(item) {
      if (item instanceof Raw) {
        return this.groupByRaw.apply(this, arguments);
      }
      this._statements.push({
        grouping: 'group',
        type: 'groupByBasic',
        value: helpers.normalizeArr.apply(null, arguments)
      });
      return this;
    },
  
    // Adds a raw `group by` clause to the query.
    groupByRaw(sql, bindings) {
      const raw = (sql instanceof Raw ? sql : this.client.raw(sql, bindings));
      this._statements.push({
        grouping: 'group',
        type: 'groupByRaw',
        value: raw
      });
      return this;
    },
  
    // Adds a `order by` clause to the query.
    orderBy(column, direction) {
      this._statements.push({
        grouping: 'order',
        type: 'orderByBasic',
        value: column,
        direction
      });
      return this;
    },
  
    // Add a raw `order by` clause to the query.
    orderByRaw(sql, bindings) {
      const raw = (sql instanceof Raw ? sql : this.client.raw(sql, bindings));
      this._statements.push({
        grouping: 'order',
        type: 'orderByRaw',
        value: raw
      });
      return this;
    },
  
    // Add a union statement to the query.
    union(callbacks, wrap) {
      if (arguments.length === 1 ||
          (arguments.length === 2 && isBoolean(wrap))) {
        if (!Array.isArray(callbacks)) {
          callbacks = [callbacks];
        }
        for (let i = 0, l = callbacks.length; i < l; i++) {
          this._statements.push({
            grouping: 'union',
            clause: 'union',
            value: callbacks[i],
            wrap: wrap || false
          });
        }
      } else {
        callbacks = toArray(arguments).slice(0, arguments.length - 1);
        wrap = arguments[arguments.length - 1];
        if (!isBoolean(wrap)) {
          callbacks.push(wrap);
          wrap = false;
        }
        this.union(callbacks, wrap);
      }
      return this;
    },
  
    // Adds a union all statement to the query.
    unionAll(callback, wrap) {
      this._statements.push({
        grouping: 'union',
        clause: 'union all',
        value: callback,
        wrap: wrap || false
      });
      return this;
    },
  
    // Adds a `having` clause to the query.
    having(column, operator, value) {
      if (column instanceof Raw && arguments.length === 1) {
        return this._havingRaw(column);
      }
  
      // Check if the column is a function, in which case it's
      // a having statement wrapped in parens.
      if (typeof column === 'function') {
        return this.havingWrapped(column);
      }
  
      this._statements.push({
        grouping: 'having',
        type: 'havingBasic',
        column,
        operator,
        value,
        bool: this._bool()
      });
      return this;
    },
    // Adds an `or having` clause to the query.
    orHaving() {
      return this._bool('or').having.apply(this, arguments);
    },
    havingRaw(sql, bindings) {
      return this._havingRaw(sql, bindings);
    },
    orHavingRaw(sql, bindings) {
      return this._bool('or').havingRaw(sql, bindings);
    },
    // Adds a raw `having` clause to the query.
    _havingRaw(sql, bindings) {
      const raw = (sql instanceof Raw ? sql : this.client.raw(sql, bindings));
      this._statements.push({
        grouping: 'having',
        type: 'havingRaw',
        value: raw,
        bool: this._bool()
      });
      return this;
    },
  
    // Only allow a single "offset" to be set for the current query.
    offset(value) {
      this._single.offset = value;
      return this;
    },
  
    // Only allow a single "limit" to be set for the current query.
    limit(value) {
      const val = parseInt(value, 10)
      if (isNaN(val)) {
        helpers.warn('A valid integer must be provided to limit')
      } else {
        this._single.limit = val;
      }
      return this;
    },
  
    // Retrieve the "count" result of the query.
    count(column) {
      return this._aggregate('count', (column || '*'));
    },
  
    // Retrieve the minimum value of a given column.
    min(column) {
      return this._aggregate('min', column);
    },
  
    // Retrieve the maximum value of a given column.
    max(column) {
      return this._aggregate('max', column);
    },
  
    // Retrieve the sum of the values of a given column.
    sum(column) {
      return this._aggregate('sum', column);
    },
  
    // Retrieve the average of the values of a given column.
    avg(column) {
      return this._aggregate('avg', column);
    },
  
    // Retrieve the "count" of the distinct results of the query.
    countDistinct(column) {
      return this._aggregate('count', (column || '*'), true);
    },
  
    // Retrieve the sum of the distinct values of a given column.
    sumDistinct(column) {
      return this._aggregate('sum', column, true);
    },
  
    // Retrieve the vg of the distinct results of the query.
    avgDistinct(column) {
      return this._aggregate('avg', column, true);
    },
  
    // Increments a column's value by the specified amount.
    increment(column, amount) {
      return this._counter(column, amount);
    },
  
    // Decrements a column's value by the specified amount.
    decrement(column, amount) {
      return this._counter(column, amount, '-');
    },
  
    // Sets the values for a `select` query, informing that only the first
    // row should be returned (limit 1).
    first() {
      const args = new Array(arguments.length);
      for (let i = 0; i < args.length; i++) {
        args[i] = arguments[i];
      }
      this.select.apply(this, args);
      this._method = 'first';
      this.limit(1);
      return this;
    },
  
    // Pluck a column from a query.
    pluck(column) {
      this._method = 'pluck';
      this._single.pluck = column;
      this._statements.push({
        grouping: 'columns',
        type: 'pluck',
        value: column
      });
      return this;
    },
  
    // Insert & Update
    // ------
  
    // Sets the values for an `insert` query.
    insert(values, returning) {
      this._method = 'insert';
      if (!isEmpty(returning)) this.returning(returning);
      this._single.insert = values
      return this;
    },
  
    // Sets the values for an `update`, allowing for both
    // `.update(key, value, [returning])` and `.update(obj, [returning])` syntaxes.
    update(values, returning) {
      let ret;
      const obj = this._single.update || {};
      this._method = 'update';
      if (isString(values)) {
        obj[values] = returning;
        if (arguments.length > 2) {
          ret = arguments[2];
        }
      } else {
        const keys = Object.keys(values);
        if (this._single.update) {
          helpers.warn('Update called multiple times with objects.')
        }
        let i = -1;
        while (++i < keys.length) {
          obj[keys[i]] = values[keys[i]]
        }
        ret = arguments[1];
      }
      if (!isEmpty(ret)) this.returning(ret);
      this._single.update = obj;
      return this;
    },
  
    // Sets the returning value for the query.
    returning(returning) {
      this._single.returning = returning;
      return this;
    },
  
    // Delete
    // ------
  
    // Executes a delete statement on the query;
    delete(ret) {
      this._method = 'del';
      if (!isEmpty(ret)) this.returning(ret);
      return this;
    },
  
  
    // Truncates a table, ends the query chain.
    truncate(tableName) {
      this._method = 'truncate';
      if (tableName) {
        this._single.table = tableName
      }
      return this;
    },
  
    // Retrieves columns for the table specified by `knex(tableName)`
    columnInfo(column) {
      this._method = 'columnInfo';
      this._single.columnInfo = column;
      return this;
    },
  
    // Set a lock for update constraint.
    forUpdate() {
      this._single.lock = 'forUpdate';
      return this;
    },
  
    // Set a lock for share constraint.
    forShare() {
      this._single.lock = 'forShare';
      return this;
    },
  
    // Takes a JS object of methods to call and calls them
    fromJS(obj) {
      each(obj, (val, key) => {
        if (typeof this[key] !== 'function') {
          helpers.warn(`Knex Error: unknown key ${key}`)
        }
        if (Array.isArray(val)) {
          this[key].apply(this, val)
        } else {
          this[key](val)
        }
      })
      return this
    },
  
    // Passes query to provided callback function, useful for e.g. composing
    // domain-specific helpers
    modify(callback) {
      callback.apply(this, [this].concat(tail(arguments)));
      return this;
    },
  
    // ----------------------------------------------------------------------
  
    // Helper for the incrementing/decrementing queries.
    _counter(column, amount, symbol) {
      let amt = parseInt(amount, 10);
      if (isNaN(amt)) amt = 1;
      this._method = 'counter';
      this._single.counter = {
        column,
        amount: amt,
        symbol: (symbol || '+')
      };
      return this;
    },
  
    // Helper to get or set the "boolFlag" value.
    _bool(val) {
      if (arguments.length === 1) {
        this._boolFlag = val;
        return this;
      }
      const ret = this._boolFlag;
      this._boolFlag = 'and';
      return ret;
    },
  
    // Helper to get or set the "notFlag" value.
    _not(val) {
      if (arguments.length === 1) {
        this._notFlag = val;
        return this;
      }
      const ret = this._notFlag;
      this._notFlag = false;
      return ret;
    },
  
    // Helper to get or set the "joinFlag" value.
    _joinType (val) {
      if (arguments.length === 1) {
        this._joinFlag = val;
        return this;
      }
      const ret = this._joinFlag || 'inner';
      this._joinFlag = 'inner';
      return ret;
    },
  
    // Helper for compiling any aggregate queries.
    _aggregate(method, column, aggregateDistinct) {
      this._statements.push({
        grouping: 'columns',
        type: 'aggregate',
        method,
        value: column,
        aggregateDistinct: aggregateDistinct || false
      });
      return this;
    }
  
  })
  
  Object.defineProperty(Builder.prototype, 'or', {
    get () {
      return this._bool('or');
    }
  });
  
  Object.defineProperty(Builder.prototype, 'not', {
    get () {
      return this._not(true);
    }
  });
  
  Builder.prototype.select = Builder.prototype.columns
  Builder.prototype.column = Builder.prototype.columns
  Builder.prototype.andWhereNot = Builder.prototype.whereNot
  Builder.prototype.andWhere = Builder.prototype.where
  Builder.prototype.andWhereRaw = Builder.prototype.whereRaw
  Builder.prototype.andWhereBetween = Builder.prototype.whereBetween
  Builder.prototype.andWhereNotBetween = Builder.prototype.whereNotBetween
  Builder.prototype.andHaving = Builder.prototype.having
  Builder.prototype.from = Builder.prototype.table
  Builder.prototype.into = Builder.prototype.table
  Builder.prototype.del = Builder.prototype.delete
  
  // Attach all of the top level promise methods that should be chainable.
  require('../interface')(Builder);
  
  export default Builder;
  