Add filtering support to increment/decrement

lib/dao.js

@@ -546,6 +546,7 @@ module.exports = (function() {
     var identifier    = this.__options.hasPrimaryKeys ? this.primaryKeyValues : { id: this.id }
       , updatedAtAttr = this.Model._timestampAttributes.updatedAt
       , values        = {}
+      , where
 
     if (countOrOptions === undefined) {
       countOrOptions = { by: 1, transaction: null }
@@ -555,9 +556,12 @@ module.exports = (function() {
 
     countOrOptions = Utils._.extend({
       by:         1,
-      attributes: {}
+      attributes: {},
+      where:      {}
     }, countOrOptions)
 
+    where = _.extend(countOrOptions.where, identifier);
+
     if (Utils._.isString(fields)) {
       values[fields] = countOrOptions.by
     } else if (Utils._.isArray(fields)) {
@@ -572,7 +576,7 @@ module.exports = (function() {
       countOrOptions.attributes[updatedAtAttr] = Utils.now(this.Model.daoFactoryManager.sequelize.options.dialect)
     }
 
-    return this.QueryInterface.increment(this, this.QueryInterface.QueryGenerator.addSchema(this.Model.tableName, this.Model.options.schema), values, identifier, countOrOptions)
+    return this.QueryInterface.increment(this, this.QueryInterface.QueryGenerator.addSchema(this.Model.tableName, this.Model.options.schema), values, where, countOrOptions)
   }
 
   DAO.prototype.decrement = function (fields, countOrOptions) {

test/dao.test.js

@@ -294,6 +294,18 @@ describe(Support.getTestDialectTeaser("DAO"), function () {
       })
     })
 
+    it('supports where conditions', function(done) {
+      var self = this
+      this.User.find(1).complete(function(err, user1) {
+        user1.increment(['aNumber'], { by: 2, where: { bNumber: 1 } }).complete(function() {
+          self.User.find(1).complete(function(err, user3) {
+            expect(user3.aNumber).to.be.equal(0)
+            done()
+          })
+        })
+      })
+    })
+
     it('with array', function(done) {
       var self = this
       this.User.find(1).complete(function(err, user1) {