diff --git a/examples/relations.js b/examples/relations.js
index ed3474cc..702a7071 100644
--- a/examples/relations.js
+++ b/examples/relations.js
@@ -3,7 +3,8 @@ var ds = new DataSource('memory');
 
 var Order = ds.createModel('Order', {
   items: [String],
-  orderDate: Date
+  orderDate: Date,
+  qty: Number
 });
 
 var Customer = ds.createModel('Customer', {
@@ -43,14 +44,17 @@ Customer.create({name: 'John'}, function (err, customer) {
 Customer.hasMany(Order, {as: 'orders', foreignKey: 'customerId'});
 
 Customer.create({name: 'Ray'}, function (err, customer) {
-  Order.create({customerId: customer.id, orderDate: new Date()}, function (err, order) {
+  Order.create({customerId: customer.id, qty: 3, orderDate: new Date()}, function (err, order) {
     order3 = order;
     customer.orders(console.log);
-    customer.orders.create({orderDate: new Date()}, function (err, order) {
+    customer.orders.create({orderDate: new Date(), qty: 4}, function (err, order) {
       console.log(order);
       Customer.include([customer], 'orders', function (err, results) {
         console.log('Results: ', results);
       });
+      customer.orders({where: {qty: 4}}, function(err, results) {
+        console.log('customer.orders', results);
+      });
       customer.orders.findById(order3.id, console.log);
       customer.orders.destroy(order3.id, console.log);
     });
diff --git a/lib/connectors/memory.js b/lib/connectors/memory.js
index da4bc2c4..ce466221 100644
--- a/lib/connectors/memory.js
+++ b/lib/connectors/memory.js
@@ -332,14 +332,31 @@ Memory.prototype.all = function all(model, filter, callback) {
 };
 
 function applyFilter(filter) {
-  if (typeof filter.where === 'function') {
-    return filter.where;
+  var where = filter.where;
+  if (typeof where === 'function') {
+    return where;
   }
-  var keys = Object.keys(filter.where);
+  var keys = Object.keys(where);
   return function (obj) {
     var pass = true;
     keys.forEach(function (key) {
-      if (!test(filter.where[key], obj && obj[key])) {
+      if(key === 'and' || key === 'or') {
+        if(Array.isArray(where[key])) {
+          if(key === 'and') {
+            pass = where[key].every(function(cond) {
+              return applyFilter({where: cond})(obj);
+            });
+            return pass;
+          }
+          if(key === 'or') {
+            pass = where[key].some(function(cond) {
+              return applyFilter({where: cond})(obj);
+            });
+            return pass;
+          }
+        }
+      }
+      if (!test(where[key], obj && obj[key])) {
         pass = false;
       }
     });
@@ -350,11 +367,14 @@ function applyFilter(filter) {
     if (typeof value === 'string' && example && example.constructor.name === 'RegExp') {
       return value.match(example);
     }
-    if (typeof example === 'undefined') return undefined;
-    if (typeof value === 'undefined') return undefined;
+    if (example === undefined || value === undefined) {
+      return undefined;
+    }
     if (typeof example === 'object') {
       // ignore geo near filter
-      if (example.near) return true;
+      if (example.near) {
+        return true;
+      }
 
       if (example.inq) {
         if (!value) return false;
diff --git a/lib/dao.js b/lib/dao.js
index bc20d505..aad2cc6c 100644
--- a/lib/dao.js
+++ b/lib/dao.js
@@ -359,7 +359,7 @@ function convertNullToNotFoundError(ctx, cb) {
 
   var modelName = ctx.method.sharedClass.name;
   var id = ctx.getArgByName('id');
-  var msg = 'Unkown "' + modelName + '" id "' + id + '".';
+  var msg = 'Unknown "' + modelName + '" id "' + id + '".';
   var error = new Error(msg);
   error.statusCode = error.status = 404;
   cb(error);
diff --git a/lib/relations.js b/lib/relations.js
index dca6170a..a18da4e9 100644
--- a/lib/relations.js
+++ b/lib/relations.js
@@ -8,7 +8,7 @@ var ModelBaseClass = require('./model.js');
 module.exports = Relation;
 
 /**
- * Relations class
+ * Relations class.  Use to define relationships between models.
  *
  * @class Relation
  */
@@ -47,12 +47,25 @@ function lookupModel(models, modelName) {
 }
 
 /**
- * Declare "hasMany" relation.
- * Example:
- * ```User.hasMany(Post, {as: 'posts', foreignKey: 'authorId'});```
+ * Define a "one to many" relationship by specifying the model name
  * 
+ * Examples:
+ * ```
+ * User.hasMany(Post, {as: 'posts', foreignKey: 'authorId'});
+ * ```
+ * 
+ * ```
+ * Book.hasMany(Chapter);
+ * ```
+ * Or, equivalently:
+ * ```
+ * Book.hasMany('chapters', {model: Chapter});
+ * ```
  * @param {Relation} anotherClass Class to has many
- * @param {Object} params Configuration {as:, foreignKey:}
+ * @options {Object} parameters Configuration parameters 
+ * @property {String} as
+ * @property {String} foreignKey Property name of foreign key field.
+ * @property {Object} model Model object
  */
 Relation.hasMany = function hasMany(anotherClass, params) {
   var thisClassName = this.modelName;
@@ -218,9 +231,28 @@ Relation.hasMany = function hasMany(anotherClass, params) {
 };
 
 /**
- * Declare "belongsTo" relation.
+ * Declare "belongsTo" relation that sets up a one-to-one connection with another model, such that each
+ * instance of the declaring model "belongs to" one instance of the other model.
  *
- * **Examples**
+ * For example, if an application includes users and posts, and each post can be written by exactly one user.
+ * The following code specifies that `Post` has a reference called `author` to the `User` model via the `userId` property of `Post`
+ * as the foreign key.
+ * ```
+ * Post.belongsTo(User, {as: 'author', foreignKey: 'userId'});
+ * ```
+ * You can then access the author in one of the following styles.
+ * Get the User object for the post author asynchronously:
+ * ```
+ * post.author(callback);
+ * ```
+ * Get the User object for the post author synchronously:
+ * ```
+ * post.author();
+ * Set the author to be the given user:
+ * ```
+ * post.author(user) 
+ * ```
+ * Examples:
  * 
  * Suppose the model Post has a *belongsTo* relationship with User (the author of the post). You could declare it this way:
  * ```js
@@ -244,7 +276,9 @@ Relation.hasMany = function hasMany(anotherClass, params) {
  * This optional parameter default value is false, so the related object will be loaded from cache if available.
  * 
  * @param {Class} anotherClass Class to belong
- * @param {Object} params Configuration {as: 'propertyName', foreignKey: 'keyName'}
+ * @param {Object} Parameters Configuration parameters
+ * @property {String} as Can be 'propertyName'
+ * @property {String} foreignKey Name of foreign key property.
  * 
  */
 Relation.belongsTo = function (anotherClass, params) {
@@ -389,15 +423,34 @@ Relation.belongsTo = function (anotherClass, params) {
 };
 
 /**
- * Many-to-many relation
- *
- * For example, this creates connection model 'PostTag':
- * ```js
- * Post.hasAndBelongsToMany('tags');
- * ``` 
+ * A hasAndBelongsToMany relation creates a direct many-to-many connection with another model, with no intervening model.
+ * For example, if your application includes users and groups, with each group having many users and each user appearing
+ * in many groups, you could declare the models this way:
+ * ```
+ *  User.hasAndBelongsToMany('groups', {model: Group, foreignKey: 'groupId'});
+ * ```
+ *  Then, to get the groups to which the user belongs:
+ * ```
+ *  user.groups(callback);
+ * ```
+ *  Create a new group and connect it with the user:
+ * ```
+ *  user.groups.create(data, callback);
+ * ```
+ *  Connect an existing group with the user:
+ * ```
+ *  user.groups.add(group, callback);
+ * ```
+ *  Remove the user from the group:
+ * ```
+ *  user.groups.remove(group, callback); 
+ * ```
+ * 
  * @param {String|Function} anotherClass - target class to hasAndBelongsToMany or name of
  * the relation
- * @param {Object} params - configuration {as: String, foreignKey: *, model: ModelClass}
+ * @options {Object} params - configuration {as: String, foreignKey: *, model: ModelClass}
+ * @property {Object} model Model name
+ * @property {String} foreignKey Property name of foreign key field.
  */
 Relation.hasAndBelongsToMany = function hasAndBelongsToMany(anotherClass, params) {
   params = params || {};
diff --git a/package.json b/package.json
index a569f21f..09efe955 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "loopback-datasource-juggler",
-  "version": "1.5.0",
+  "version": "1.5.1",
   "description": "LoopBack DataSoure Juggler",
   "keywords": [
     "StrongLoop",
diff --git a/test/basic-querying.test.js b/test/basic-querying.test.js
index 9b90d66d..ae72ca45 100644
--- a/test/basic-querying.test.js
+++ b/test/basic-querying.test.js
@@ -131,6 +131,50 @@ describe('basic-querying', function () {
       });
     });
 
+    it('should support "and" operator that is satisfied', function (done) {
+      User.find({where: {and: [
+        {name: 'John Lennon'},
+        {role: 'lead'}
+      ]}}, function (err, users) {
+        should.not.exist(err);
+        users.should.have.property('length', 1);
+        done();
+      });
+    });
+
+    it('should support "and" operator that is not satisfied', function (done) {
+      User.find({where: {and: [
+        {name: 'John Lennon'},
+        {role: 'member'}
+      ]}}, function (err, users) {
+        should.not.exist(err);
+        users.should.have.property('length', 0);
+        done();
+      });
+    });
+
+    it('should support "or" that is satisfied', function (done) {
+      User.find({where: {or: [
+        {name: 'John Lennon'},
+        {role: 'lead'}
+      ]}}, function (err, users) {
+        should.not.exist(err);
+        users.should.have.property('length', 2);
+        done();
+      });
+    });
+
+    it('should support "or" operator that is not satisfied', function (done) {
+      User.find({where: {or: [
+        {name: 'XYZ'},
+        {role: 'Hello1'}
+      ]}}, function (err, users) {
+        should.not.exist(err);
+        users.should.have.property('length', 0);
+        done();
+      });
+    });
+
     it('should only include fields as specified', function (done) {
       var remaining = 0;