diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index ac1b854..37fa525 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -2,15 +2,8 @@
 <project version="4">
   <component name="ChangeListManager">
     <list default="true" id="585b6f0a-0d20-4a3c-825b-5f85848cbf40" name="Default" comment="">
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/.idea/guoren.iml" afterPath="$PROJECT_DIR$/.idea/guoren.iml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/.idea/workspace.xml" afterPath="$PROJECT_DIR$/.idea/workspace.xml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/Gemfile" afterPath="$PROJECT_DIR$/Gemfile" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/Gemfile.lock" afterPath="$PROJECT_DIR$/Gemfile.lock" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/controllers/main_controller.rb" afterPath="$PROJECT_DIR$/app/controllers/main_controller.rb" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/helpers/main_helper.rb" afterPath="$PROJECT_DIR$/app/helpers/main_helper.rb" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/views/layouts/_nav.html.erb" afterPath="$PROJECT_DIR$/app/views/layouts/_nav.html.erb" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/views/main/main.html.erb" afterPath="$PROJECT_DIR$/app/views/main/main.html.erb" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/public/stylesheets/mystyle.css" afterPath="$PROJECT_DIR$/public/stylesheets/mystyle.css" />
     </list>
     <ignored path="guoren.iws" />
     <ignored path=".idea/workspace.xml" />
@@ -39,11 +32,11 @@
   </component>
   <component name="FileEditorManager">
     <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-      <file leaf-file-name="Gemfile" pinned="false" current-in-tab="false">
+      <file leaf-file-name="Gemfile" pinned="false" current-in-tab="true">
         <entry file="file://$PROJECT_DIR$/Gemfile">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="303">
-              <caret line="34" column="0" selection-start-line="34" selection-start-column="0" selection-end-line="34" selection-end-column="0" />
+            <state relative-caret-position="626">
+              <caret line="53" column="0" selection-start-line="53" selection-start-column="0" selection-end-line="53" selection-end-column="0" />
               <folding />
             </state>
           </provider>
@@ -52,11 +45,9 @@
       <file leaf-file-name="main.html.erb" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/views/main/main.html.erb">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="629">
+            <state relative-caret-position="1547">
               <caret line="91" column="16" selection-start-line="91" selection-start-column="16" selection-end-line="91" selection-end-column="16" />
-              <folding>
-                <element signature="n#div#0;n#div#0;n#div#0;n#div#0;n#!!top" expanded="false" />
-              </folding>
+              <folding />
             </state>
           </provider>
         </entry>
@@ -74,7 +65,7 @@
       <file leaf-file-name="view_helpers.rb" pinned="false" current-in-tab="false">
         <entry file="file://$USER_HOME$/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/will_paginate-3.1.5/lib/will_paginate/view_helpers.rb">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="-241">
+            <state relative-caret-position="1292">
               <caret line="76" column="95" selection-start-line="76" selection-start-column="87" selection-end-line="76" selection-end-column="95" />
               <folding />
             </state>
@@ -91,10 +82,10 @@
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="_nav.html.erb" pinned="false" current-in-tab="true">
+      <file leaf-file-name="_nav.html.erb" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/views/layouts/_nav.html.erb">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="374">
+            <state relative-caret-position="170">
               <caret line="37" column="17" selection-start-line="37" selection-start-column="17" selection-end-line="37" selection-end-column="17" />
               <folding />
             </state>
@@ -114,7 +105,7 @@
       <file leaf-file-name="main_helper.rb" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/helpers/main_helper.rb">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="643">
+            <state relative-caret-position="1020">
               <caret line="60" column="0" selection-start-line="60" selection-start-column="0" selection-end-line="60" selection-end-column="0" />
               <folding />
             </state>
@@ -124,7 +115,7 @@
       <file leaf-file-name="instrumentation.rb" pinned="false" current-in-tab="false">
         <entry file="file://$USER_HOME$/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/actionpack-5.0.0.1/lib/action_controller/metal/instrumentation.rb">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="322">
+            <state relative-caret-position="765">
               <caret line="45" column="0" selection-start-line="45" selection-start-column="0" selection-end-line="45" selection-end-column="0" />
               <folding />
             </state>
@@ -134,7 +125,7 @@
       <file leaf-file-name="mystyle.css" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/public/stylesheets/mystyle.css">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="651">
+            <state relative-caret-position="2363">
               <caret line="139" column="1" selection-start-line="139" selection-start-column="1" selection-end-line="139" selection-end-column="1" />
               <folding />
             </state>
@@ -164,13 +155,13 @@
         <option value="$PROJECT_DIR$/public/stylesheets/style.css" />
         <option value="$PROJECT_DIR$/.gitignore" />
         <option value="$PROJECT_DIR$/高级软件工程TODOList.md" />
-        <option value="$PROJECT_DIR$/Gemfile" />
         <option value="$PROJECT_DIR$/app/helpers/main_helper.rb" />
         <option value="$USER_HOME$/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/will_paginate-3.1.5/lib/will_paginate/view_helpers.rb" />
         <option value="$PROJECT_DIR$/public/stylesheets/mystyle.css" />
         <option value="$PROJECT_DIR$/app/views/main/main.html.erb" />
         <option value="$PROJECT_DIR$/app/controllers/main_controller.rb" />
         <option value="$PROJECT_DIR$/app/views/layouts/_nav.html.erb" />
+        <option value="$PROJECT_DIR$/Gemfile" />
       </list>
     </option>
   </component>
@@ -514,24 +505,25 @@
       <workItem from="1482662034465" duration="18070000" />
       <workItem from="1482733701322" duration="75000" />
       <workItem from="1482733804592" duration="3749000" />
+      <workItem from="1482738643416" duration="217000" />
     </task>
     <servers />
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="23675000" />
+    <option name="totallyTimeSpent" value="23892000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="0" y="23" width="1440" height="873" extended-state="6" />
-    <editor active="true" />
+    <editor active="false" />
     <layout>
-      <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.20243205" sideWeight="0.49292928" order="0" side_tool="false" content_ui="combo" />
+      <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.20529328" sideWeight="0.49292928" order="0" side_tool="false" content_ui="combo" />
       <window_info id="TODO" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="6" side_tool="false" content_ui="tabs" />
       <window_info id="Event Log" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.30111524" sideWeight="0.50858366" order="7" side_tool="true" content_ui="tabs" />
       <window_info id="Database" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="3" side_tool="false" content_ui="tabs" />
       <window_info id="Version Control" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="false" content_ui="tabs" />
-      <window_info id="Run" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3283767" sideWeight="0.49713877" order="2" side_tool="false" content_ui="tabs" />
+      <window_info id="Run" active="true" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.3283767" sideWeight="0.49713877" order="2" side_tool="false" content_ui="tabs" />
       <window_info id="Structure" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.24964234" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
-      <window_info id="Terminal" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.30111524" sideWeight="0.4914163" order="7" side_tool="false" content_ui="tabs" />
+      <window_info id="Terminal" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.30111524" sideWeight="0.4914163" order="7" side_tool="false" content_ui="tabs" />
       <window_info id="Favorites" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.19670959" sideWeight="0.5070707" order="2" side_tool="true" content_ui="tabs" />
       <window_info id="Debug" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.39900866" sideWeight="0.49570817" order="3" side_tool="false" content_ui="tabs" />
       <window_info id="Cvs" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
@@ -584,7 +576,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="1173">
           <caret line="69" column="15" selection-start-line="69" selection-start-column="15" selection-end-line="69" selection-end-column="15" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -592,7 +583,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="32266">
           <caret line="1898" column="0" selection-start-line="1898" selection-start-column="0" selection-end-line="1898" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -600,7 +590,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="1071">
           <caret line="63" column="0" selection-start-line="63" selection-start-column="0" selection-end-line="63" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -608,9 +597,7 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="3604">
           <caret line="212" column="54" selection-start-line="212" selection-start-column="54" selection-end-line="212" selection-end-column="54" />
-          <folding>
-            <element signature="n#div#0;n#div#0;n#div#0;n#div#0;n#!!top" expanded="false" />
-          </folding>
+          <folding />
         </state>
       </provider>
     </entry>
@@ -634,7 +621,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="1173">
           <caret line="69" column="15" selection-start-line="69" selection-start-column="15" selection-end-line="69" selection-end-column="15" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -642,7 +628,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="32266">
           <caret line="1898" column="0" selection-start-line="1898" selection-start-column="0" selection-end-line="1898" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -650,7 +635,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="0">
           <caret line="0" column="0" selection-start-line="0" selection-start-column="0" selection-end-line="0" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -658,9 +642,7 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="3604">
           <caret line="212" column="54" selection-start-line="212" selection-start-column="54" selection-end-line="212" selection-end-column="54" />
-          <folding>
-            <element signature="n#div#0;n#div#0;n#div#0;n#div#0;n#!!top" expanded="false" />
-          </folding>
+          <folding />
         </state>
       </provider>
     </entry>
@@ -693,7 +675,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="0">
           <caret line="0" column="0" selection-start-line="0" selection-start-column="0" selection-end-line="0" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -830,7 +811,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="32266">
           <caret line="1898" column="0" selection-start-line="1898" selection-start-column="0" selection-end-line="1898" selection-end-column="0" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -838,7 +818,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="1173">
           <caret line="69" column="15" selection-start-line="69" selection-start-column="15" selection-end-line="69" selection-end-column="15" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -846,7 +825,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="43">
           <caret line="38" column="27" selection-start-line="38" selection-start-column="27" selection-end-line="38" selection-end-column="27" />
-          <folding />
         </state>
       </provider>
     </entry>
@@ -871,7 +849,7 @@
     </entry>
     <entry file="file://$USER_HOME$/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/actionpack-5.0.0.1/lib/action_controller/metal/instrumentation.rb">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="322">
+        <state relative-caret-position="765">
           <caret line="45" column="0" selection-start-line="45" selection-start-column="0" selection-end-line="45" selection-end-column="0" />
           <folding />
         </state>
@@ -887,7 +865,7 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/app/helpers/main_helper.rb">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="643">
+        <state relative-caret-position="1020">
           <caret line="60" column="0" selection-start-line="60" selection-start-column="0" selection-end-line="60" selection-end-column="0" />
           <folding />
         </state>
@@ -895,23 +873,15 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/public/stylesheets/mystyle.css">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="651">
+        <state relative-caret-position="2363">
           <caret line="139" column="1" selection-start-line="139" selection-start-column="1" selection-end-line="139" selection-end-column="1" />
           <folding />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/Gemfile">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="303">
-          <caret line="34" column="0" selection-start-line="34" selection-start-column="0" selection-end-line="34" selection-end-column="0" />
-          <folding />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$USER_HOME$/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/will_paginate-3.1.5/lib/will_paginate/view_helpers.rb">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="-241">
+        <state relative-caret-position="1292">
           <caret line="76" column="95" selection-start-line="76" selection-start-column="87" selection-end-line="76" selection-end-column="95" />
           <folding />
         </state>
@@ -935,21 +905,27 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/app/views/main/main.html.erb">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="629">
+        <state relative-caret-position="1547">
           <caret line="91" column="16" selection-start-line="91" selection-start-column="16" selection-end-line="91" selection-end-column="16" />
-          <folding>
-            <element signature="n#div#0;n#div#0;n#div#0;n#div#0;n#!!top" expanded="false" />
-          </folding>
+          <folding />
         </state>
       </provider>
     </entry>
     <entry file="file://$PROJECT_DIR$/app/views/layouts/_nav.html.erb">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="374">
+        <state relative-caret-position="170">
           <caret line="37" column="17" selection-start-line="37" selection-start-column="17" selection-end-line="37" selection-end-column="17" />
           <folding />
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/Gemfile">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="626">
+          <caret line="53" column="0" selection-start-line="53" selection-start-column="0" selection-end-line="53" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
   </component>
 </project>
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index efd58e0..3241b63 100644
--- a/Gemfile
+++ b/Gemfile
@@ -48,9 +48,9 @@ group :development do
   gem 'spring-watcher-listen', '~> 2.0.0'
 end
 
-# group :production do
-#   gem 'pg','~> 0.18.4'
-# end
+group :production do
+  gem 'pg','~> 0.18.4'
+end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
diff --git a/Gemfile.lock b/Gemfile.lock
index 89b5d45..4acc3f8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -86,6 +86,8 @@ GEM
       mini_portile2 (~> 2.1.0)
     nokogiri (1.6.8.1-x64-mingw32)
       mini_portile2 (~> 2.1.0)
+    pg (0.18.4)
+    pg (0.18.4-x64-mingw32)
     puma (3.6.2)
     rack (2.0.1)
     rack-test (0.6.3)
@@ -172,6 +174,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails
   listen (~> 3.0.5)
+  pg (~> 0.18.4)
   puma (~> 3.0)
   rails (~> 5.0.0, >= 5.0.0.1)
   rake