TeeChart Example?

Comments

• waeberd

  November 2007 edited 2:58PM

  Ok, I have found out the following:
  
  * FastReport expects one db-rowset per teechart-series
  * for radar series FastReport expects a "LABEL / ANGLE / VALUE" rowformat
  
  Consequences:
  * I need one query per series
  * if I want to use radar series, I need to change the sql from
  

  SELECT *
    FROM teechartdata
   WHERE teechartdata_id = 10
  

  
  to
  

  SELECT   *
      FROM (SELECT 'Cars' label, 0 angle, cars VALUE
              FROM teechartdata
             WHERE teechartdata_id = 10
            UNION
            SELECT 'Phones' label, 72 angle, phones VALUE
              FROM teechartdata
             WHERE teechartdata_id = 10
            UNION
            SELECT 'Tables' label, 144 angle, TABLES VALUE
              FROM teechartdata
             WHERE teechartdata_id = 10
            UNION
            SELECT 'Monitors' label, 216 angle, monitors VALUE
              FROM teechartdata
             WHERE teechartdata_id = 10
            UNION
            SELECT 'Lamps' label, 288 angle, lamps VALUE
              FROM teechartdata
             WHERE teechartdata_id = 10)
  ORDER BY angle
  

  
  ... which is of course very bad SQL-coding (too complicated, too many queries).
  
  How can I simplify this? Read the data from the simple "SELECT *" query and add the series-data
  by script?
  
  Please help!
  
  Daniel
• gordk St.Catherines On. Canada.

  November 2007 edited 2:58PM

  create the series in the chart editor
  then in the onbeforeprintmethod of the chart object.
  use the add method to add values to each series.
  tip you can connect the query to a hiddendataband set to 1 record
  then in the obpevent of the chart object write code to iterate through the dataset and add the values to the series'.
  begin
  masterdata1.dataset.first;
  for i = 0 to masterdata1.dataset.recordcount-1 do
  begin
  code to add values to series[0];
  code to add values to series[1];
  code to add values to series[2];
  masterdata1.dataset.next;
  next;
  end;
  see the usermanual on working with charts.
  
• waeberd

  November 2007 edited 2:58PM

  Excellent, thanks for pointing the directions, Gord!
  
  works fine, here's my scripting code (in case somebody's interested... :-) ):
  

  procedure BuildRadarSeries(series: TfrxSeriesItem);
  var
    j: integer;
    nAngle: integer;                                     
    strSep: string;
    qry: TfrxODACQuery;
    strFieldName: string;                                               
  begin
    strSep := '';
    qry := TfrxODACQuery(invisibleBand.Dataset);                               
    if qry.FieldsCount > 0 then
      nAngle := 360 div qry.FieldsCount
    else
      nAngle := 0;                                                 
    for j := 0 to qry.FieldsCount -1 do
    begin
      strFieldName := qry.Fields[j].FieldName;
      { Source1: "LABEL"}                                                           
      series.Source1 := series.Source1 + strSep + strFieldName;                                                                                                                                                           
      { Source2: "ANGLE"}                                                           
      series.Source2 := series.Source2 + strSep + IntToStr(j * nAngle);
      { Source3: "VALUE"}                                                           
      series.Source3 := series.Source3 + strSep + IntToStr(qry.Value[strFieldName]);                                                                                                                                                           
      strSep := ';';                                        
    end;                  
  end;
  
  
  procedure Chart1OnBeforePrint(Sender: TfrxComponent);
  var
    i: integer;                                
  begin
    i := 0;                             
    with invisibleBand.Dataset do
    begin                    
      First;
      while not eof do
      begin
        BuildRadarSeries(Chart1.SeriesData[i]);                                                                         
        Inc(i);                      
        Next;
      end;  
    end;              
  end;
  
  begin
  
  end.
  

  
  Cheers, Daniel