Microsoft Enterprise Library--activation error occured while trying to get instance of type Database

            Database db = Databasefactory.createdatabase ();
            DbCommand DC = db. Getstoredproccommand ("proc", parameters);
            dc. ExecuteNonQuery ();
            int a= (int) db. Getparametervalue (DC, "returnvalue");

            return 0;

Using the Microsoft Enterprise Library, when executing to create DATABASE, will report activation error occured while trying to get instance of type Database error

This is because Web.cong is not configured correctly

  <configSections>
    <section name= "dataconfiguration" type= " Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, version=5.0.414.0, culture=neutral, publickeytoken=31bf3856ad364e35 " Requirepermission= "true"/>
  </configSections>
  <dataconfiguration defaultdatabase= "DBInstance "/>
  <connectionStrings>
    <add name=" dbinstance "connectionstring=" data source= database name; Initial Catalog=online;uid=sa;pwd=sa; "
      Providername= "System.Data.SqlClient"/>
  </connectionStrings>

Check your Web. config Enterprise Library configuration is correct, if like above to configure, can solve the problem of instance error