急，求救！ 怎么用ADOQuery, ADOTable 读写oracle大字段？

Question

怎么用ADOQuery, ADOTable 读写oracle大字段？我在使用的时候报“数据类型不支持”。

Answer 1

注意区分sql语句字段的大小写。

Answer 2

用OLE代碼如下：（樓主本人的）//Save Paper
procedure TfrmResPaper.bbnSavePaperClick(Sender: TObject);
var
    Query:TADOQuery;
    Stream:TADOBlobStream;
begin
    if not ((OlePaper.State=osLoaded) and
        (DMResPaper.State=dsBrowse) and (DMResPaper.RecordCount>0))  then Exit;
    Query:=TADOQuery.Create(nil);
    with Query do
    begin
        Connection:=Pubconn;
        SQL.Clear;
        SQL.Add('SELECT ID,RES_NO,PAPER FROM B_PAPER WHERE ID='+DMResPaper.FieldByName('ID').AsString
                +' AND RES_NO='''+DMResPaper.FieldByName('RES_NO').AsString+'''');
        Open;
        Edit;
        Stream:=TADOBlobStream.Create(TBlobField(FieldByName('PAPER')),bmReadWrite);
        try
            try
                OlePaper.SaveToStream(Stream);
            finally
                Stream.Free;
            end;
            Post;
            EpsDLG('圖紙保存成功!');
        except
            EpsDLG('圖紙保存失敗!');
        end;
        Query.Free;
    end;
end;//Load Paper
procedure TfrmResPaper.dgMainDblClick(Sender: TObject);
var
    Query:TADOQuery;
    Stream:TADOBlobStream;
begin
  inherited;
  if not ((DMResPaper.State=dsBrowse) and (DMResPaper.RecordCount>0))  then Exit;
    Query:=TADOQuery.Create(nil);
    with Query do
    begin
        Connection:=Pubconn;
        SQL.Clear;
        SQL.Add('SELECT ID,RES_NO,PAPER FROM B_PAPER WHERE ID='+DMResPaper.FieldByName('ID').AsString
                +' AND RES_NO='''+DMResPaper.FieldByName('RES_NO').AsString+''' AND PAPER IS NOT NULL');
        Open;
        if RecordCount=0 then
            OlePaper.DestroyObject
        else
        begin
            Stream:=TADOBlobStream.Create(TBlobField(FieldByName('PAPER')),bmRead);
            try
                OlePaper.LoadFromStream(Stream);
            finally
                Stream.Free;
            end;
        end;
        Query.Free;
    end;
end;
參考
http://expert.csdn.net/Expert/topic/2483/2483251.xml?temp=.4762842

Answer 3

使用TBlobField，TADOBlobStream等对象实现。