1 reply to this topic

[littlebigfred]

Hello

I have a couple of questions on how to go creating columns in a NextGrid from a dataset:

1. Is there a two-column list that maps NextGrid column types to compatible Delphi datatypes, eg. "TNxTextColumn = String", "TNxCheckBoxColumn = String, Boolean", "TNxNumberColumn = Integer, Double", etc.?

2. Is there a simple way to display the datatype returned by the dataset, and create a compatible column in a grid?

Here's the current code:

CODE

ASQLite3Query1.SQL.Text := 'SELECT * FROM mytable';
ASQLite3Query1.Open;

for mycol := 0 to ASQLite3Query1.FieldCount - 1 do begin
  //======== The quick way to see how wrapper maps SQLite to Delphi
  //E2250 There is no overloaded version of 'IntToStr' that can be called with these arguments
  //ShowMessage(IntToStr(ASQLite3Query1.Fields[mycol].DataType));

  //E2089 Invalid typecast
  //ShowMessage(String(ASQLite3Query1.Fields[mycol].DataType));

  //======== The longer way...
  case ASQLite3Query1.Fields[mycol].DataType of
    ftString:
      Columns.Add(TNxTextColumn,'My Col1');
    ftSmallint:
      Columns.Add(TNxNumberColumn,'My Col1');
    ftInteger:
      Columns.Add(TNxNumberColumn,'My Col1');
    ftWord:
      Columns.Add(TNxNumberColumn,'My Col1');
    etc.
  else
    ShowMessage('Other type');
  end;
end;

Thank you.

[Boki (Berg)]

Hello Franky,

Only solution is to determine DataType (as you have done with case structure) and then set ColumnClass to desired type of column.

I suggest that you look for procedure TNextDBGrid.CreateColumns; inside NxDBGrid.pas . You will see how I have done this.

I hope that this helps