diff --git a/lib/dao.js b/lib/dao.js
index 85741acc..3191bc19 100644
--- a/lib/dao.js
+++ b/lib/dao.js
@@ -59,7 +59,8 @@ DataAccessObject._forDB = function (data) {
     }
     var res = {};
     Object.keys(data).forEach(function (propName) {
-        if (this.whatTypeName(propName) === 'JSON' || data[propName] instanceof Array) {
+        var type = this.whatTypeName(propName);
+        if (type === 'JSON' || type === 'Any' || type === 'Object' || data[propName] instanceof Array) {
             res[propName] = JSON.stringify(data[propName]);
         } else {
             res[propName] = data[propName];
diff --git a/lib/datasource.js b/lib/datasource.js
index 6c3f3d12..56b1fdf6 100644
--- a/lib/datasource.js
+++ b/lib/datasource.js
@@ -319,6 +319,16 @@ DataSource.prototype.createModel = DataSource.prototype.define = function define
     properties = properties || {};
     settings = settings || {};
 
+    if(this.isRelational()) {
+        // Set the strict mode to be true for relational DBs by default
+        if(settings.strict === undefined || settings.strict === null) {
+            settings.strict = true;
+        }
+        if(settings.strict === false) {
+            settings.strict = 'throw';
+        }
+    }
+
     var NewClass = ModelBuilder.prototype.define.call(this, className, properties, settings);
 
     // add data access objects
diff --git a/lib/model-builder.js b/lib/model-builder.js
index 58ecedae..bf6995c6 100644
--- a/lib/model-builder.js
+++ b/lib/model-builder.js
@@ -94,6 +94,11 @@ ModelBuilder.prototype.define = function defineClass(className, properties, sett
     properties = properties || {};
     settings = settings || {};
 
+    // Set the strict mode to be false by default
+    if(settings.strict === undefined || settings.strict === null) {
+        settings.strict = false;
+    }
+
     this.buildSchema(className, properties);
 
     // every class can receive hash of data as optional param
diff --git a/lib/model.js b/lib/model.js
index 77cd1100..77f13e1c 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -163,8 +163,13 @@ ModelBaseClass.defineProperty = function (prop, params) {
 
 ModelBaseClass.whatTypeName = function (propName) {
     var prop = this.properties[propName];
-    if (!prop || !prop.type) {
-        throw new Error('Undefined type for ' + this.modelName + ':' + propName);
+    if(!prop) {
+        // The property is not part of the definition
+        return null;
+    }
+    if (!prop.type) {
+        throw new Error('Type not defined for property ' + this.modelName + '.' + propName);
+        // return null;
     }
     return prop.type.name;
 };
diff --git a/test/basic-querying.test.js b/test/basic-querying.test.js
index f1dcfb6a..2c617a03 100644
--- a/test/basic-querying.test.js
+++ b/test/basic-querying.test.js
@@ -320,12 +320,12 @@ function seed(done) {
     var beatles = [
         {
             name: 'John Lennon',
-            mail: 'john@b3atl3s.co.uk',
+            email: 'john@b3atl3s.co.uk',
             role: 'lead',
             order: 2
         }, {
             name: 'Paul McCartney',
-            mail: 'paul@b3atl3s.co.uk',
+            email: 'paul@b3atl3s.co.uk',
             role: 'lead',
             order: 1
         },
diff --git a/test/loopback-dl.test.js b/test/loopback-dl.test.js
index 45abf3fb..9292fa06 100644
--- a/test/loopback-dl.test.js
+++ b/test/loopback-dl.test.js
@@ -11,7 +11,6 @@ describe('ModelBuilder define model', function () {
     it('should be able to define plain models', function (done) {
         var modelBuilder = new ModelBuilder();
 
-        // simplier way to describe model
         var User = modelBuilder.define('User', {
             name: String,
             bio: ModelBuilder.Text,
@@ -29,7 +28,6 @@ describe('ModelBuilder define model', function () {
         modelBuilder.definitions.should.be.a('object').and.have.property('User');
 
         var user = new User({name: 'Joe', age: 20});
-        // console.log(user);
 
         User.modelName.should.equal('User');
         user.should.be.a('object').and.have.property('name', 'Joe');
@@ -42,15 +40,12 @@ describe('ModelBuilder define model', function () {
     it('should not take unknown properties in strict mode', function (done) {
         var modelBuilder = new ModelBuilder();
 
-        // simplier way to describe model
         var User = modelBuilder.define('User', {name: String, bio: String}, {strict: true});
 
         var user = new User({name: 'Joe', age: 20});
-        // console.log(user);
 
         User.modelName.should.equal('User');
         user.should.be.a('object');
-        // console.log(user);
         assert(user.name === 'Joe');
         assert(user.age === undefined);
         assert(user.toObject().age === undefined);
@@ -59,14 +54,41 @@ describe('ModelBuilder define model', function () {
         done(null, User);
     });
 
+    it('should throw when unknown properties are used if strict=throw', function (done) {
+        var modelBuilder = new ModelBuilder();
+
+        var User = modelBuilder.define('User', {name: String, bio: String}, {strict: 'throw'});
+
+        try {
+            var user = new User({name: 'Joe', age: 20});
+            assert(false, 'The code should have thrown an error');
+        } catch(e) {
+            assert(true, 'The code is expected to throw an error');
+        }
+        done(null, User);
+    });
+
     it('should be able to define open models', function (done) {
         var modelBuilder = new ModelBuilder();
 
-        // simplier way to describe model
         var User = modelBuilder.define('User', {}, {strict: false});
 
         var user = new User({name: 'Joe', age: 20});
-        // console.log(user);
+
+        User.modelName.should.equal('User');
+        user.should.be.a('object').and.have.property('name', 'Joe');
+        user.should.have.property('name', 'Joe');
+        user.should.have.property('age', 20);
+        user.should.not.have.property('bio');
+        done(null, User);
+    });
+
+    it('should use false as the default value for strict', function (done) {
+        var modelBuilder = new ModelBuilder();
+
+        var User = modelBuilder.define('User', {});
+
+        var user = new User({name: 'Joe', age: 20});
 
         User.modelName.should.equal('User');
         user.should.be.a('object').and.have.property('name', 'Joe');
@@ -115,7 +137,6 @@ describe('ModelBuilder define model', function () {
                 emails: [{label: 'work', email: 'xyz@sample.com'}],
                 friends: ['Mary', 'John']
         });
-        // console.log(user);
 
         User.modelName.should.equal('User');
         user.should.be.a('object').and.have.property('name', 'Joe');
@@ -149,13 +170,13 @@ describe('DataSource define model', function () {
             title: { type: String, length: 255 },
             content: { type: DataSource.Text },
             date: { type: Date, default: function () {
-                return new Date;
+                return new Date();
             } },
             timestamp: { type: Number, default: Date.now },
             published: { type: Boolean, default: false, index: true }
         });
 
-// simplier way to describe model
+// simpler way to describe model
         var User = ds.define('User', {
             name: String,
             bio: DataSource.Text,
@@ -164,15 +185,17 @@ describe('DataSource define model', function () {
             age: Number
         });
 
-        var Group = ds.define('Group', {name: String});
+        var Group = ds.define('Group', {group: String});
+        User.mixin(Group);
 
 // define any custom method
         User.prototype.getNameAndAge = function () {
             return this.name + ', ' + this.age;
         };
 
-        var user = new User({name: 'Joe'});
-        // console.log(user);
+        var user = new User({name: 'Joe', group: 'G1'});
+        assert.equal(user.name, 'Joe');
+        assert.equal(user.group, 'G1');
 
         // setup relationships
         User.hasMany(Post, {as: 'posts', foreignKey: 'userId'});
@@ -183,7 +206,6 @@ describe('DataSource define model', function () {
 
         var user2 = new User({name: 'Smith'});
         user2.save(function (err) {
-            // console.log(user2);
             var post = user2.posts.build({title: 'Hello world'});
             post.save(function (err, data) {
                 // console.log(err ? err : data);
@@ -199,9 +221,7 @@ describe('DataSource define model', function () {
                 console.log(err);
                 return;
             }
-            // console.log(data);
             var post = data.posts.build({title: 'My Post'});
-            // console.log(post);
         });
 
         User.create({name: 'Ray'}, function (err, data) {
@@ -244,6 +264,104 @@ describe('DataSource define model', function () {
         });
 
     });
+
+    it('should not take unknown properties in strict mode', function (done) {
+        var ds = new DataSource('memory');
+
+        var User = ds.define('User', {name: String, bio: String}, {strict: true});
+
+        User.create({name: 'Joe', age: 20}, function (err, user) {
+
+            User.modelName.should.equal('User');
+            user.should.be.a('object');
+            assert(user.name === 'Joe');
+            assert(user.age === undefined);
+            assert(user.toObject().age === undefined);
+            assert(user.toObject(true).age === undefined);
+            assert(user.bio === undefined);
+            done(null, User);
+        });
+    });
+
+    it('should throw when unknown properties are used if strict=throw', function (done) {
+        var ds = new DataSource('memory');
+
+        var User = ds.define('User', {name: String, bio: String}, {strict: 'throw'});
+
+        try {
+            var user = new User({name: 'Joe', age: 20});
+            assert(false, 'The code should have thrown an error');
+        } catch(e) {
+            assert(true, 'The code is expected to throw an error');
+        }
+        done(null, User);
+    });
+
+    it('should be able to define open models', function (done) {
+        var ds = new DataSource('memory');
+
+        var User = ds.define('User', {}, {strict: false});
+
+        User.create({name: 'Joe', age: 20}, function (err, user) {
+
+            User.modelName.should.equal('User');
+            user.should.be.a('object').and.have.property('name', 'Joe');
+            user.should.have.property('name', 'Joe');
+            user.should.have.property('age', 20);
+            user.should.not.have.property('bio');
+            done(null, User);
+        });
+    });
+
+    it('should use false as the default value for strict', function (done) {
+        var ds = new DataSource('memory');
+
+        var User = ds.define('User', {});
+
+        User.create({name: 'Joe', age: 20}, function (err, user) {
+
+            User.modelName.should.equal('User');
+            user.should.be.a('object').and.have.property('name', 'Joe');
+            user.should.have.property('name', 'Joe');
+            user.should.have.property('age', 20);
+            user.should.not.have.property('bio');
+            done(null, User);
+        });
+    });
+
+    it('should use true as the default value for strict for relational DBs', function (done) {
+        var ds = new DataSource('memory');
+        ds.connector.relational = true; // HACK
+
+        var User = ds.define('User', {name: String, bio: String}, {strict: true});
+
+        var user = new User({name: 'Joe', age: 20});
+
+        User.modelName.should.equal('User');
+        user.should.be.a('object');
+        assert(user.name === 'Joe');
+        assert(user.age === undefined);
+        assert(user.toObject().age === undefined);
+        assert(user.toObject(true).age === undefined);
+        assert(user.bio === undefined);
+        done(null, User);
+    });
+
+    it('should throw when unknown properties are used if strict=false for relational DBs', function (done) {
+        var ds = new DataSource('memory');
+        ds.connector.relational = true; // HACK
+
+        var User = ds.define('User', {name: String, bio: String}, {strict: 'throw'});
+
+        try {
+            var user = new User({name: 'Joe', age: 20});
+            assert(false, 'The code should have thrown an error');
+        } catch(e) {
+            assert(true, 'The code is expected to throw an error');
+        }
+        done(null, User);
+    });
+
 });
 
 
@@ -286,7 +404,7 @@ describe('Load models from json', function () {
         models.should.have.property('Customer');
         for (var s in models) {
             var m = models[s];
-            // console.log(m.modelName, new m());
+            assert(new m());
         }
     });
 });