网络对数据库断线怎么处理异常

Question

通过网络对数据库 进行操作 突然断线  怎么处理异常
代码如下：
procedure threed_up.updateonerow(str_sql:string;ado_db:tadoquery;str_key:tstrings;str_tablename:string);
vari,i_list,i_count,i_loop:integer;
b_succ:boolean;       //更新一个表中的一条记录
begin
         
        
            if service_update.ADOQ_exec.RecordCount=0 then
            begin               service_update.ADOCom_exec.CommandText:=
               insert_sql(ado_db,str_tablename);
               try
               service_update.ADOCom_exec.Execute ;
               except
               //b_succ:=false;
               b_do:=false;
               service_update.writeerror(datetostr(date())+' '+timetostr(time())+'插入记录到'+str_tablename+'表出错');
               end;
            end
            else
            begin                service_update.ADOQ_exec.SQL.Text :='';
                service_update.ADOCom_exec.CommandText:=
                update_sql(ado_db,str_tablename,str_key);
                try
                service_update.ADOCom_exec.Execute();
                except
                //b_succ:=false;
                b_do:=false;
                service_update.writeerror(datetostr(date())+' '+timetostr(time())+'修改记录到'+str_tablename+'表出错');
                end;
              end;
             if (str_tablename<>'OILCAN_INFO')  then
             begin
             ado_db.Edit ;
             ado_db.FieldByName(str_tag).Value :=1;
             ado_db.Post ;
             end;
        end;end;这个过程在 网络断开  时常发现死了   请大虾帮忙找找原因  给点建议