Entity Framework does not add / save to database -

i searched alot problem, hadn't found anything!

i created database , table , connect form entityframework those..

when type data informations , click on add button, database doesn't add new row ...

(these codes)

main code:

   using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.threading.tasks; using system.windows.forms; using system.data.entity.validation; using system.diagnostics;  namespace windowsformsapplication6 {     public partial class buyform : form     {         public buyform()         {             initializecomponent();          }          private void buyform_load(object sender, eventargs e)         {           }         notebookentities database = new notebookentities();            private void buygridview_cellcontentclick(object sender, datagridviewcelleventargs e)         {          }          private void buyform_load_1(object sender, eventargs e)         {          }          private void textbox6_textchanged(object sender, eventargs e)         {          }          private void button1_click(object sender, eventargs e)         {              buytbl tbl = new buytbl()             {                 name = bnametextbox.text,                  price = int.parse(bpricetextbox.text),                 date = datetimepicker1.value,                 deadline = datetimepicker2.value,                 buyername = bbuyertextbox.text,                 count = int.parse(bcounttextbox.text)                };             if (bpricetextbox == null)             {                 string = "the field null!";                 messagebox.show(a);             }              database.buytbls.add(tbl);             datagridview1.datasource = database.buytbls.tolist();          }     } } 

app.config

    <?xml version="1.0" encoding="utf-8"?> <configuration>   <configsections>     <!-- more information on entity framework configuration, visit http://go.microsoft.com/fwlink/?linkid=237468 -->     <section name="entityframework" type="system.data.entity.internal.configfile.entityframeworksection, entityframework, version=6.0.0.0, culture=neutral, publickeytoken=b77a5c561934e089" requirepermission="false" />   </configsections>   <startup>     <supportedruntime version="v4.0" sku=".netframework,version=v4.5" />   </startup>   <connectionstrings>     <add name="masterentities" connectionstring="metadata=res://*/model1.csdl|res://*/model1.ssdl|res://*/model1.msl;provider=system.data.sqlclient;provider connection string=&quot;data source=smq2;integrated security=true;multipleactiveresultsets=true;app=entityframework&quot;" providername="system.data.entityclient" />     <add name="notebookentities" connectionstring="metadata=res://*/namadmodel.csdl|res://*/namadmodel.ssdl|res://*/namadmodel.msl;provider=system.data.sqlclient;provider connection string=&quot;data source=smq2;initial catalog=notebook;integrated security=true;multipleactiveresultsets=true;app=entityframework&quot;" providername="system.data.entityclient" />   </connectionstrings>   <entityframework>     <defaultconnectionfactory type="system.data.entity.infrastructure.localdbconnectionfactory, entityframework">       <parameters>         <parameter value="mssqllocaldb" />       </parameters>     </defaultconnectionfactory>     <providers>       <provider invariantname="system.data.sqlclient" type="system.data.entity.sqlserver.sqlproviderservices, entityframework.sqlserver" />     </providers>   </entityframework> </configuration> 

thank guys!...

when do

database.buytbls.add(tbl); 

you add entity database context

but commit added entity, need do

database.savechanges();