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Question

下面是程序CODE，
unit demo3;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, DBCtrls, Grids, DBGrids, DB, ADODB;type
  TForm1 = class(TForm)
    ADOConnection1: TADOConnection;
    ADODataSet1: TADODataSet;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    DBNavigator1: TDBNavigator;
    rgFieldNames: TRadioGroup;
    cbSearchValue: TComboBox;
    Button1: TButton;
    ADODataSet2: TADODataSet;
    procedure ADODataSet1AfterOpen(DataSet: TDataSet);
    procedure Button1Click(Sender: TObject);
    procedure rgFieldNamesClick(Sender: TObject);
  private
    { Private declarations }
    procedure FillFieldNames;
    procedure FillSearchValues;
    function GetSearchField:string;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}
procedure TForm1.FillFieldNames;
var
   iCount:integer;
begin
   rgFieldNames.Items.Clear;
   for iCount:=0 to ADODataSet1.Fields.Count-1 do
   begin
      rgFieldNames.Items.Add(ADODataSet1.Fields[iCount].FieldName);
   end;
   rgFieldNames.ItemIndex:=0;
end;
function TForm1.GetSearchField:string;
begin
   result:=ADODataSet1.Fields[rgFieldNames.ItemIndex].fieldName;
end;procedure TForm1.FillSearchValues;
begin
    try
       ADODataSet2.close;
       ADODataSet2.commandText:='select '+GetSearchField +
       'from 客户';
       ADODataSet2.Open;
       cbSearchValue.Items.clear;
       while not ADODataSet2.EOF do
       begin
          cbSearchValue.items.add(ADODataSet2.Fields[0].AsString);
          ADODataSet2.Next;
       end;
       finally
       ADODataSet2.close;
       end;
end;
procedure TForm1.ADODataSet1AfterOpen(DataSet: TDataSet);
begin
    FillFieldNames;
    FillSearchValues;
end;procedure TForm1.rgFieldNamesClick(Sender: TObject);
begin
        FillSearchValues;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
         ADODataSet1.Locate(GetSearchField,cbSearchValue.Text,
                           [loCaseInsensitive,loPartialKey]);end;
end.报错：
missing connection or connectionstring
请问如何解决

Answer 1

Ado的连接字符串设置好了没有？

Answer 2

没连接数据库，
ado的connect没连接或连接错了

Answer 3

设置ADOConnection1的connectionstring
设置ADODataSet1的connection为ADOConnection1

Answer 4

你们说的我都做了，也检查了，没有问题，我怀疑是不是在ADODataSet2.commandText:='select '+GetSearchField +
       'from 客户';
这个地方出了问题
我总觉得GetSearchField在程序开启的时候有点问题

Answer 5

设置ADOConnection1的connectionstring
设置ADODataSet1、ADODataSet2的connection为ADOConnection1
肯定是这的问题
你再调调
而且用ADOConnection1连库时测试一下看看是否连接成功！！！