Knowledge Base Article

KB10259 - How can I construct an ADOJoin to an external attribute table and then programatically set up the renderer to render the shapes in a layer based on a value in a field in this table? Could you send me sample code to show me how?

Sure:



sqlDC := CreateOleObject('ADODB.Connection');

sqlRS := CreateOleObject('ADODB.Recordset');

sqlDC.Open('FILEDSN=GMINY.DSN');

sqlRS.Open('select id, agri FROM QTocounty ORDER BY id', sqlDC);

// order by ID is important!!!!



// ll is your layer with a unique 'zone' field

ll.ADOJoin := sqlRS;

ll.ADOJoinPrimary := 'zone';

ll.ADOJoinForeign := 'id';



ll.RenderExpression := 'age'; // if our external database has such field.

ll.RenderMinVal := 0;

ll.RenderMaxVal := 100;

ll.RenderZones := -5; // crucial - must be something.



ll.RenderColorDefault := clBlue; // is nothing match

ll.UseConfig := False; // turn off config file suggestion

ll.RenderStartColor := clwhite;

ll.RenderEndColor := clGreen;

ll.AreaColor := GIS_RENDER_COLOR;

ll.AreaOutlineWidth:=0;

Created: 2003-11-21, Modified: 2005-09-14