Let's just use ONE type of updateQuery

lib/dialects/abstract/dialect.js

+var AbstractDialect = function() {
+	
+}
+
+AbstractDialect.prototype.supports = {
+	'RETURNING *': false
+}
+
+module.exports = AbstractDialect
\ No newline at end of file

lib/dialects/abstract/query-generator.js

@@ -122,8 +122,29 @@ module.exports = (function() {
                    OR a string with conditions (e.g. 'name="foo"').
                    If you use a string, you have to escape it on your own.
     */
-    updateQuery: function(tableName, values, where) {
-      throwMethodUndefined('updateQuery')
+    updateQuery: function(tableName, attrValueHash, where, options, attributes) {
+      attrValueHash = Utils.removeNullValuesFromHash(attrValueHash, this.options.omitNull, options)
+
+      var query
+        , values = []
+
+      query = "UPDATE <%= table %> SET <%= values %> WHERE <%= where %>"
+      if (this._dialect.supports['RETURNING']) {
+        query += " RETURNING *"
+      }
+
+      for (var key in attrValueHash) {
+        var value = attrValueHash[key]
+        values.push(this.quoteIdentifier(key) + "=" + this.escape(value, (!!attributes && !!attributes[key] ? attributes[key] : undefined)))
+      }
+
+      var replacements = {
+        table:  this.quoteIdentifiers(tableName),
+        values: values.join(","),
+        where:  this.getWhereConditions(where)
+      }
+
+      return Utils._.template(query)(replacements)
     },
 
     /*

lib/dialects/mariadb.js

+var _ = require('lodash')
+  , MySQL = require('./mysql')
+
+var MariaDialect = function(sequelize) {
+  this.sequelize = sequelize
+}
+
+MariaDialect.prototype = _.extend({
+
+}, MySQL.prototype)
+
+module.exports = MariaDialect
\ No newline at end of file

lib/dialects/mysql.js

+var _ = require('lodash')
+  , Abstract = require('./abstract/dialect')
+
+var MysqlDialect = function(sequelize) {
+  this.sequelize = sequelize
+}
+
+MysqlDialect.prototype.supports = _.extend(Abstract.prototype.supports, {
+
+})
+
+module.exports = MysqlDialect
\ No newline at end of file

lib/dialects/mysql/query-generator.js

@@ -204,25 +204,6 @@ module.exports = (function() {
       return Utils._.template(query)(replacements)
     },
 
-    updateQuery: function(tableName, attrValueHash, where, options) {
-      attrValueHash = Utils.removeNullValuesFromHash(attrValueHash, this.options.omitNull, options)
-
-      var values = []
-
-      for (var key in attrValueHash) {
-        var value  = attrValueHash[key]
-          , _value = this.escape(value)
-
-        values.push(this.quoteIdentifier(key) + "=" + _value)
-      }
-
-      var query = "UPDATE " + this.quoteIdentifier(tableName) +
-                  " SET " + values.join(",") +
-                  " WHERE " + this.getWhereConditions(where)
-
-      return query
-    },
-
     deleteQuery: function(tableName, where, options) {
       options = options || {}
 

lib/dialects/postgres.js

+var _ = require('lodash')
+  , Abstract = require('./abstract/dialect')
+
+var PostgresDialect = function(sequelize) {
+  this.sequelize = sequelize
+}
+
+PostgresDialect.prototype.supports = _.extend(Abstract.prototype.supports, {
+	'RETURNING': true
+})
+
+module.exports = PostgresDialect
\ No newline at end of file

lib/dialects/postgres/query-generator.js

@@ -332,26 +332,6 @@ module.exports = (function() {
       return Utils._.template(query)(replacements)
     },
 
-    updateQuery: function(tableName, attrValueHash, where, options, attributes) {
-      attrValueHash = Utils.removeNullValuesFromHash(attrValueHash, this.options.omitNull, options)
-
-      var query  = "UPDATE <%= table %> SET <%= values %> WHERE <%= where %> RETURNING *"
-        , values = []
-
-      for (var key in attrValueHash) {
-        var value = attrValueHash[key]
-        values.push(this.quoteIdentifier(key) + "=" + this.escape(value, (!!attributes && !!attributes[key] ? attributes[key] : undefined)))
-      }
-
-      var replacements = {
-        table:  this.quoteIdentifiers(tableName),
-        values: values.join(","),
-        where:  this.getWhereConditions(where)
-      }
-
-      return Utils._.template(query)(replacements)
-    },
-
     deleteQuery: function(tableName, where, options, factory) {
       options = options || {}
 

lib/dialects/sqlite.js

+var _ = require('lodash')
+  , Abstract = require('./abstract/dialect')
+
+var SqliteDialect = function(sequelize) {
+  this.sequelize = sequelize
+}
+
+SqliteDialect.prototype.supports = _.extend(Abstract.prototype.supports, {
+
+})
+
+module.exports = SqliteDialect
\ No newline at end of file

lib/query-interface.js

@@ -8,6 +8,7 @@ module.exports = (function() {
     this.sequelize              = sequelize
     this.QueryGenerator         = require('./dialects/' + this.sequelize.options.dialect + '/query-generator')
     this.QueryGenerator.options = this.sequelize.options
+    this.QueryGenerator._dialect = this.sequelize.dialect
   }
   Utils.addEventEmitter(QueryInterface)
 

lib/sequelize.js

@@ -112,6 +112,11 @@ module.exports = (function() {
       dialectOptions: this.options.dialectOptions,
     }
 
+    try {
+      this.dialect            = new (require("./dialects/" + this.getDialect()))(this)
+    } catch(err) {
+      throw new Error("The dialect " + this.getDialect() + " is not supported.")
+    }
     this.daoFactoryManager  = new DAOFactoryManager(this)
     this.transactionManager = new TransactionManager(this)