sql - Cannot insert the data into the table C# visual studio 2013 -

i want write data local database table. when run code there no erros , when count rows after insert statement message box shows me row inserted. when close programm , in database there no new rows.

i'm using c# , visual studio 2013.

do know problem is?

thank you.

string connection = "data source=(localdb)\\v11.0;attachdbfilename=|datadirectory|\\datenbank.mdf;integrated security=true;connect timeout=30";              sqlconnection cnn = new sqlconnection(connection);             cnn.open();              string query = "insert customer (id, name) values (@id, @name)";             sqlcommand command = new sqlcommand(query, cnn);              command.parameters.addwithvalue("@id", 1);             command.parameters.addwithvalue("@name", 'john');             sqldatareader reader;              command.executenonquery();              query = "select count(id) customer";             command = new sqlcommand(query, cnn);              reader = command.executereader();              while (reader.read())             {                 messagebox.show(reader[0].tostring());             }              reader.close(); 

try this:

  try {         int rowsaffected = command.executenonquery();         if (0 < rowsaffected)             messagebox.show("success!");         else             messagebox.show("failed!");     } catch (sqlexception ex) {        messagebox.show(ex.message);     } {         if (cnn.state == connectionstate.open)             cnn.close();     } 

also refer: why saving changes database fails?