Question:
I am trying to populate a comboxbox from a table (or query). If I use dataware is only receive the first record, I however want all records in the field I select. I have done this in the following VB code;Private Sub Form_Load()Dim RecEmployees as RecordsetDim MyDB as DatabaseSet MyDB = OpenDatabase _ (“D:database.mdb”)Set Recemployees = MyDB.OpenRecordset(“Employees”)Dim i as integer For i = 0 to RecEmployees.RecordCount – 1 Combo1.AddItem (RecEmployees(1)) RecEmployee.MoveNext Next iEnd SubBut have been unable to duplicate in Object Pascal.Any assistance would be greatly appreciated.Thanks,James
Answer:
In Delphi, it’s basically the same principle. Here are a couple of function that I’ve written that will seamlessly do the job:
procedure DBLoadListBox( dbSource, {database name} tblSource, {table name} fldName : String; {field name to load from} const LBox: TStrings);{List Box on Form}var SourceTbl : TTable;begin SourceTbl := TTable.Create(Application); {Create an instance of sourceTbl} with SourceTbl do begin Active := False; DatabaseName := dbSource; TableName := tblSource; try Open; First; while NOT EOF do begin LBox.Add(SourceTbl.FieldByName(fldName).AsString); Next; end; finally Free; end; end;end;procedure DBLoadList(tblSource, {table name} fldName : String; {field name to load from} const List : TStrings); {Any TStrings}var qry : TQuery;begin qry := TQuery.Create(nil); with qry do begin Active := False; DatabaseName := ExtractFilePath(tblSource); SQL.Add('SELECT DISTINCT d."' + fldName + '" '); SQL.Add('FROM "' + tblSource + '" d'); try Open; while NOT EOF do begin List.Add(FieldByName(fldName).AsString); Next; end; finally Free; end; end;end;
The first function accesses a table directly, while the second uses a query – very useful for when you only want the DISTINCT values from a particular field.
