diff --git a/lib/far_mar/Market.rb b/lib/far_mar/Market.rb
index f804f194..a497baf0 100644
--- a/lib/far_mar/Market.rb
+++ b/lib/far_mar/Market.rb
@@ -1,6 +1,66 @@
 require './lib/far_mar'
+require 'pry'
 module FarMar
   class Market
-
+    attr_reader :id, :name, :address, :city, :county, :state, :zip
+    def initialize(id, name, address, city, county, state, zip)
+      @id = id.to_i
+      @name = name
+      @address = address
+      @city = city
+      @county = county
+      @state = state
+      @zip = zip
+    end
+    def self.all
+      @@markets_all ||= []
+      if @@markets_all == []
+        CSV.read("./support/markets.csv").map do |row|
+          @@markets_all.push(FarMar::Market.new(row[0], row[1], row[2], row[3], row[4], row[5], row[6]))
+        end
+      end
+      return @@markets_all
+    end
+    def self.find(id)
+      FarMar::Market.all.find do |market|
+        market.id == id
+      end
+    end
+    def vendors
+      FarMar::Vendor.all.find_all do |vendor|
+        self.id == vendor.market_id
+      end
+    end
+    def products
+      products = []
+      vendors.map do |vendor|
+        vendor.products.map do |product|
+          products.push(product)
+        end
+      end
+      return products
+    end
+    def self.search(search_term)
+      search_term = search_term.downcase
+      matching_markets = []
+      all.each do |market|
+        matching_markets.push(market) if (market.name.downcase.include? search_term) && !(matching_markets.include? market)
+      end
+      FarMar::Vendor.all.each do |vendor|
+        matching_markets.push(vendor.market) if (vendor.name.downcase.include? search_term) && !(matching_markets.include? vendor.market)
+      end
+      return matching_markets
+    end
+    def preferred_vendor(date = nil)
+      if date == nil
+        vendors.max_by do |vendor|
+          vendor.revenue
+        end
+      else
+        vendors.max_by do |vendor|
+          vendor.revenue(date)
+        end
+      end
+    end
   end
 end
diff --git a/lib/far_mar/Product.rb b/lib/far_mar/Product.rb
index 5377c1bd..aa8c98bd 100644
--- a/lib/far_mar/Product.rb
+++ b/lib/far_mar/Product.rb
@@ -1,6 +1,43 @@
 require './lib/far_mar'
 module FarMar
   class Product
-
+    attr_reader :id, :name, :vendor_id
+    def initialize(id, name, vendor_id)
+      @id = id.to_i
+      @name = name
+      @vendor_id = vendor_id.to_i
+    end
+    def self.all
+      @@products_all ||= []
+      if @@products_all == []
+        CSV.read("./support/products.csv").map do |row|
+          @@products_all.push(self.new(row[0], row[1], row[2]))
+        end
+      end
+      return @@products_all
+    end
+    def self.find(id)
+      all.find do |product|
+        product.id == id
+      end
+    end
+    def vendor
+      Vendor.all.find do |vendor|
+        vendor.id == self.vendor_id
+      end
+    end
+    def sales
+      Sale.all.find_all do |sale|
+        sale.product_id == self.id
+      end
+    end
+    def number_of_sales
+      sales.length
+    end
+    def self.by_vendor(vendor_id)
+      self.all.find_all do |product|
+        product.vendor_id == vendor_id
+      end
+    end
   end
 end
diff --git a/lib/far_mar/Sale.rb b/lib/far_mar/Sale.rb
index 9f967839..4e20ee60 100644
--- a/lib/far_mar/Sale.rb
+++ b/lib/far_mar/Sale.rb
@@ -1,6 +1,44 @@
 require './lib/far_mar'
 module FarMar
   class Sale
-
+    attr_reader :id, :amount, :purchase_time, :vendor_id, :product_id
+    def initialize(id, amount, purchase_time, vendor_id, product_id)
+      @id = id.to_i
+      @amount = amount.to_i
+      @purchase_time = DateTime.strptime(purchase_time, "%Y-%m-%d %H:%M:%S %z")
+      @vendor_id = vendor_id.to_i
+      @product_id = product_id.to_i
+    end
+    def self.all
+      @@sales_all ||= []
+      if @@sales_all == []
+        CSV.read("./support/sales.csv").map do |row|
+          @@sales_all.push(FarMar::Sale.new(row[0], row[1], row[2], row[3], row[4]))
+        end
+      end
+      return @@sales_all
+    end
+    def self.find(id)
+      all.find do |sale|
+        sale.id == id
+      end
+    end
+    def vendor
+      Vendor.all.find do |vendor|
+        vendor.id == self.vendor_id
+      end
+    end
+    def product
+      Product.all.find do |product|
+        product.id == self.product_id
+      end
+    end
+    def self.between(beginning_time, end_time)
+      beginning_time = DateTime.strptime(beginning_time, "%Y-%m-%d %H:%M:%S %z")
+      end_time = DateTime.strptime(end_time, "%Y-%m-%d %H:%M:%S %z")
+      self.all.find_all do |sale|
+        sale.purchase_time > beginning_time && sale.purchase_time < end_time
+      end
+    end
   end
 end
diff --git a/lib/far_mar/Vendor.rb b/lib/far_mar/Vendor.rb
index 2b2338f1..9d4d8fea 100644
--- a/lib/far_mar/Vendor.rb
+++ b/lib/far_mar/Vendor.rb
@@ -1,6 +1,62 @@
 require './lib/far_mar'
 module FarMar
   class Vendor
-
+    attr_reader :id, :name, :num_employees, :market_id
+    def initialize(id, name, num_employees, market_id)
+      @id = id.to_i
+      @name = name
+      @num_employees = num_employees.to_i
+      @market_id = market_id.to_i
+    end
+    def self.all
+      @@vendors_all ||= []
+      if @@vendors_all == []
+        CSV.read("./support/vendors.csv").map do |row|
+          @@vendors_all.push(FarMar::Vendor.new(row[0], row[1], row[2], row[3]))
+        end
+      end
+      return  @@vendors_all
+    end
+    def self.find(id)
+      all.find do |vendor|
+        vendor.id == id
+      end
+    end
+    def market
+      Market.all.find do |market|
+        market.id == self.market_id
+      end
+    end
+    def products
+      Product.all.find_all do |product|
+        product.vendor_id == self.id
+      end
+    end
+    def sales
+      Sale.all.find_all do |sale|
+        sale.vendor_id == self.id
+      end
+    end
+    def revenue(date = nil)
+      if date == nil
+        amounts = self.sales.map do |sale|
+          sale.amount
+        end
+      else
+        date = DateTime.parse(date)
+        amounts = []
+        sales.each do |sale|
+          if sale.purchase_time.to_date == date.to_date
+            amounts.push(sale.amount)
+          end
+        end
+      end
+      amounts.inject(0) { |result, sale| result + sale }
+    end
+    def self.by_market(market_id)
+      self.all.find_all do |vendor|
+        market_id == vendor.market_id
+      end
+    end
   end
 end
diff --git a/spec/far_mar/Market_spec.rb b/spec/far_mar/Market_spec.rb
index 53003bca..4124d751 100644
--- a/spec/far_mar/Market_spec.rb
+++ b/spec/far_mar/Market_spec.rb
@@ -1,11 +1,76 @@
 require 'spec_helper'
+require 'pry'
 describe FarMar::Market do
   before :each do
-    @market = FarMar::Market.new
+    @market = FarMar::Market.new("500", "Montefiore Medical Center Farmers Market_Thursday", "111 E. 210th Street", "Bronx", "Bronx", "New York", "10467")
   end
   describe "#new" do
     it "creates a new Market instance" do
       expect(@market).to be_an_instance_of FarMar::Market
     end
   end
+  describe "#all" do
+    it "creates new Market instances" do
+      expect(FarMar::Market.all[0].id).to eq 1
+    end
+    it "returns a collection representing all the markets in the CSV" do
+      expect(FarMar::Market.all.length).to eq 500
+    end
+  end
+  describe "#find(id)" do
+    it "returns the market instance with an id matching the parameter" do
+      expect(FarMar::Market.find(9).id).to eq 9
+    end
+  end
+  describe ".vendors" do
+    it "returns collection of all vendor instances with market_id matching market instance's id" do
+      expect(@market.vendors.length).to eq 10
+    end
+    it "returns a collection of vendor instances" do
+      expect(@market.vendors[0].class).to eq FarMar::Vendor
+    end
+  end
+  describe ".products" do
+    it "returns a collection of product instances associated through vendors" do
+      #vendor ids: 2681, 2682, 2683, 2684, 2685, 2686, 2687, 2688, 2689, 2690
+      expect(@market.products.length).to eq 34
+    end
+  end
+  describe "#search(search_term)" do
+    it "returns market instances where the market name contains search_term" do
+      expect(FarMar::Market.search('braintree')[0].id).to eq 36
+    end
+    it "returns market instances where the vendor name contains search_term" do
+      expect(FarMar::Market.search("Eenhol")[1].id).to eq 21
+    end
+    it "returns all market and vendor instances where search_term is within the market or vendor name only" do
+      search = FarMar::Market.search("johns")
+      # 3 markets with "johns" in name
+      # 25 vendors with "johns" in name
+      expect(search.length).to eq 28
+    end
+    it "returns only market instances" do
+      search = FarMar::Market.search("johns")
+      incorrect_class = search.find_all do |instance|
+        instance.class != FarMar::Market
+        end
+      expect(incorrect_class).to eq []
+    end
+    it "returns empty array if no search results" do
+      expect(FarMar::Market.search("a;oeaifhgsoifgj ~~~")).to eq []
+    end
+    it "does not duplicate (if same market and vendor)" do
+      expect(FarMar::Market.search("").length).to eq 500
+    end
+  end
+  describe ".preferred_vendor" do
+    it "returns the vendor with the highest revenue" do
+      expect(@market.preferred_vendor.id).to eq 2684
+    end
+  end
+  describe ".preferred_vendor(date)" do
+    it "returns the vendor with the highest revenue for date passed in" do
+      expect(@market.preferred_vendor("2013-11-09").id).to eq 2687
+    end
+  end
 end
diff --git a/spec/far_mar/Product_spec.rb b/spec/far_mar/Product_spec.rb
index 32cf098d..da0a87ed 100644
--- a/spec/far_mar/Product_spec.rb
+++ b/spec/far_mar/Product_spec.rb
@@ -1,11 +1,45 @@
 require 'spec_helper'
 describe FarMar::Product do
   before :each do
-    @product = FarMar::Product.new
+    @product = FarMar::Product.new("8188", "Brief Carrots", "2689")
   end
   describe "#new" do
     it "creates a new Product instance" do
       expect(@product).to be_an_instance_of FarMar::Product
     end
   end
+  describe "#all" do
+    it "creates new Product instances" do
+      expect(FarMar::Product.all[0].name).to eq "Dry Beets"
+    end
+    it "returns a collection representing all the products in the CSV" do
+      expect(FarMar::Product.all.length).to eq 8193
+    end
+  end
+  describe "#find(id)" do
+    it "returns the product instance with an id matching the parameter" do
+      expect(FarMar::Product.find(14).id).to eq 14
+    end
+  end
+  describe ".vendor" do
+    it "returns the vendor instance whose id matches the product's vendor_id" do
+      expect(@product.vendor.id).to eq 2689
+    end
+  end
+  describe ".sales" do
+    it "returns a collection of sales instances whose product_id matches the product's id" do
+      expect(@product.sales.length).to eq 2
+    end
+  end
+  describe ".number_of_sales" do
+    it "returns number of sales instances whose product_id matches the product's id" do
+      expect(@product.number_of_sales).to eq 2
+    end
+  end
+  describe "#by_vendor(vendor_id)" do
+    it "returns all product instances whose vendor_id matches the parameter passed in" do
+      vendor = FarMar::Product.by_vendor(2672)
+      expect(vendor.length).to eq 4
+    end
+  end
 end
diff --git a/spec/far_mar/Sale_spec.rb b/spec/far_mar/Sale_spec.rb
index 70ba0c60..39c5a695 100644
--- a/spec/far_mar/Sale_spec.rb
+++ b/spec/far_mar/Sale_spec.rb
@@ -1,11 +1,61 @@
 require 'spec_helper'
 describe FarMar::Sale do
   before :each do
-    @sale = FarMar::Sale.new
+    @sale = FarMar::Sale.new("3339", "7316", "2013-11-11 13:56:55 -0800", "742", "2213")
   end
   describe "#new" do
     it "creates a new Sale instance" do
       expect(@sale).to be_an_instance_of FarMar::Sale
     end
   end
+  describe "#all" do
+    it "creates new Sale instances" do
+      expect(FarMar::Sale.all[1].amount).to eq 2262
+    end
+    it "returns a collection representing all sales in the CSV" do
+      expect(FarMar::Sale.all.length).to eq 12798
+    end
+  end
+  describe "#find(id)" do
+    it "returns the sales instance with an id matching the parameter" do
+      expect(FarMar::Sale.find(20).id).to eq 20
+    end
+  end
+  describe ".vendor" do
+    it "returns the vendor instance whose id matches the sale's vendor_id" do
+      expect(@sale.vendor.id).to eq 742
+    end
+  end
+  describe ".product" do
+    it "returns the product instance whose id matches the sales's product_id" do
+      expect(@sale.product.id).to eq 2213
+    end
+  end
+  describe "#between(beginning_time, end_time)" do
+    context "when beginning_time is before end_time" do
+      begin_time = "2013-11-06 08:47:12 -0800"
+      end_time = "2013-11-06 08:52:59 -0800"
+      it "returns a collection of sales instances" do
+        expect(FarMar::Sale.between(begin_time, end_time)[1].class).to eq FarMar::Sale
+      end
+      it "returns all sales that occurred between beginning_time and end_time (exclusive)" do
+        expect(FarMar::Sale.between(begin_time, end_time).length).to eq 4
+        expect(FarMar::Sale.between(begin_time, end_time)[1].id).to eq 4119
+      end
+    end
+    context "when end_time is before beginning_time" do
+      it "returns an empty array" do
+        begin_time = "2013-11-06 08:52:59 -0800"
+        end_time = "2013-11-06 08:47:12 -0800"
+        expect(FarMar::Sale.between(begin_time, end_time)).to eq []
+      end
+    end
+    context "when beginning_time and end_time are the same" do
+      it "returns an empty array" do
+        begin_time = "2013-11-06 08:47:12 -0800"
+        end_time = "2013-11-06 08:47:12 -0800"
+        expect(FarMar::Sale.between(begin_time, end_time)).to eq []
+      end
+    end
+  end
 end
diff --git a/spec/far_mar/Vendor_spec.rb b/spec/far_mar/Vendor_spec.rb
index ddf4476d..475c6221 100644
--- a/spec/far_mar/Vendor_spec.rb
+++ b/spec/far_mar/Vendor_spec.rb
@@ -1,11 +1,72 @@
 require 'spec_helper'
 describe FarMar::Vendor do
   before :each do
-    @vendor = FarMar::Vendor.new
+    @vendor = FarMar::Vendor.new("2689", "Durgan-Moen", "1", "500")
   end
   describe "#new" do
     it "creates a new Vendor instance" do
       expect(@vendor).to be_an_instance_of FarMar::Vendor
     end
   end
+  describe "#all" do
+    it "creates a new Vendor instance" do
+      expect(FarMar::Vendor.all[3].market_id).to eq 1
+    end
+    it "returns a collection representing all vendors in CSV" do
+      expect(FarMar::Vendor.all.length).to eq 2690
+    end
+  end
+  describe "#find(id)" do
+    it "returns the vendor instance with an id matching the parameter" do
+      expect(FarMar::Vendor.find(556).id).to eq 556
+    end
+  end
+  describe ".market" do
+    it "returns the market instance whose id matches the vendor's market_id" do
+      expect(@vendor.market.id).to eq 500
+    end
+  end
+  describe ".products" do
+    it "returns all product instances whose vendor_id matches the vendor's id" do
+      expect(@vendor.products.length).to eq 5
+    end
+  end
+  describe ".sales" do
+    it "returns all sales instances whose vendor_id matches the vendor's id" do
+      expect(@vendor.sales.length).to eq 2
+    end
+  end
+  describe "#by_market(market_id)" do
+    it "returns all vendor instances whose market_id matches the parameter passed in" do
+      vendors = FarMar::Vendor.by_market(498)
+      expect(vendors.length).to eq 2
+    end
+  end
+  describe ".revenue(date)" do
+    context "when no date parameter is passed in" do
+      it "returns total revenue from all dates" do
+        expect(@vendor.revenue).to eq 7586
+      end
+      it "returns 0 when vendor had no sales" do
+        @vendor_0_sales = FarMar::Vendor.new("51", "Bernier Inc", "1", "12")
+        expect(@vendor_0_sales.revenue).to eq 0
+      end
+    end
+    context "when no sales happened on date" do
+      it "returns 0" do
+        expect(@vendor.revenue("2013-11-09")).to eq 0
+      end
+    end
+    context "when 1 sale happened on date" do
+      it "returns the sale amount" do
+        expect(@vendor.revenue("2013-11-10")).to eq 3793
+      end
+    end
+    context "when multiple sales happened on date" do
+      it "returns the sum of sales amounts for the date" do
+        @vendor2 = FarMar::Vendor.new("2687", "Pacocha Group", "5", "500")
+        expect(@vendor2.revenue("2013-11-12")).to eq 20781
+      end
+    end
+  end
 end
diff --git a/support/markets.csv b/support/markets.csv
index 6a265cd0..9eff6fb4 100644
--- a/support/markets.csv
+++ b/support/markets.csv
@@ -497,4 +497,4 @@
 497,Nevada County Farmers Market,11078 West First Street North,Prescott,Nevada,Arkansas,71857
 498,Morningside Park Farmers Market,110th Street & Manhattan Avenue,Mornignside Heights,New York,New York,10027
 499,Fletcher Allen's Farmers' Market,111 Colchester Ave 204 EN3,Burlington,Chittenden,Vermont,5401
-500,Montefiore Medical Center Farmers Market_Thursday,111 E. 210th Street,Bronx,Bronx,New York,10467
\ No newline at end of file
+500,Montefiore Medical Center Farmers Market_Thursday,111 E. 210th Street,Bronx,Bronx,New York,10467