remove any previously defined pks in join table model

lib/associations/has-many.js

@@ -44,6 +44,7 @@ module.exports = (function() {
   // or in an extra table which connects two tables
   HasMany.prototype.injectAttributes = function() {
     var multiAssociation = this.target.associations.hasOwnProperty(this.associationAccessor)
+      , self = this
     this.identifier = this.options.foreignKey || Utils._.underscoredIf(Utils.singularize(this.source.tableName, this.source.options.language) + "Id", this.options.underscored)
 
     // is there already a single sided association between the source and the target?
@@ -70,6 +71,14 @@ module.exports = (function() {
 
       if (this.hasJoinTableModel === true) {
         this.connectorDAO = this.options.joinTableModel
+
+        // remove any previously defined PKs
+        Utils._.each(this.connectorDAO.attributes, function(dataTypeString, attributeName) {
+          if (dataTypeString.toString().indexOf('PRIMARY KEY') !== -1) {
+            delete self.connectorDAO.rawAttributes[attributeName]
+          }
+        })
+
         this.connectorDAO.rawAttributes = Utils._.merge(this.connectorDAO.rawAttributes, combinedTableAttributes)
         this.connectorDAO.init(this.connectorDAO.daoFactoryManager)
       } else {