SELECT count(*) AS counted FROM `tabelle` WHERE SQRT(POW(`lat` - '54' , 2) + _
  POW(`lng` - '13', 2)) * 100 < 100 AND id_id = '1'

System.ArgumentOutOfRangeException: Index and length must refer to a location _
  within the string.
Parameter name: length
   at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, _
     Boolean fAlwaysCopy)
   at MySql.Data.MySqlClient.MySqlTokenizer.NextParameter()
   at MySql.Data.MySqlClient.Statement.InternalBindParameters(String sql, _
     MySqlParameterCollection parameters, MySqlPacket packet)
   at MySql.Data.MySqlClient.Statement.BindParameters()
   at MySql.Data.MySqlClient.PreparableStatement.Execute()
   at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior _
     behavior)
   at MySql.Data.MySqlClient.MySqlCommand.ExecuteScalar()
   at Test.Listener.count_scalar(String statement)