Fixes #644

lib/dialects/postgres/query-generator.js

@@ -292,7 +292,18 @@ module.exports = (function() {
       attrValueHash = Utils.removeNullValuesFromHash(attrValueHash, this.options.omitNull)
       attrValueHash = Utils.removeNullValuesFromHash(attrValueHash, this.options.omitNull)
 
 
       var query     = "INSERT INTO <%= table %> (<%= attributes %>) VALUES (<%= values %>) RETURNING *;"
       var query     = "INSERT INTO <%= table %> (<%= attributes %>) VALUES (<%= values %>) RETURNING *;"
-        , returning = removeSerialsFromHash(tableName, attrValueHash)
+
+      // Remove serials that are null or undefined, which causes an error in PG
+      Utils._.forEach(attrValueHash, function(value, key, hash) {
+        if (tables[tableName]) {
+          switch (tables[tableName][key]) {
+            case 'bigserial':
+            case 'serial':
+              if ([null, undefined].indexOf(hash[key]) !== -1) delete hash[key]
+              break
+          }
+        }
+      });
 
 
       var replacements  = {
       var replacements  = {
         table:      this.quoteIdentifiers(tableName)
         table:      this.quoteIdentifiers(tableName)

spec/dao-factory.spec.js

@@ -518,6 +518,17 @@ describe(Helpers.getTestDialectTeaser("DAOFactory"), function() {
       })
       })
     })
     })
 
 
+    it('allows setting custom IDs', function (done) {
+      this.User.create({ id: 42 }).success(function (user) {
+        expect(user.id).toEqual(42)
+
+        this.User.find(42).success(function (user) {
+          expect(user).toBeDefined()
+          done()
+        })
+      }.bind(this))
+    })
+
     describe('enums', function() {
     describe('enums', function() {
       before(function(done) {
       before(function(done) {
         this.Item = this.sequelize.define('Item', {
         this.Item = this.sequelize.define('Item', {