sql9.txt

到目前为止

Delphi 与SQL编程(二)(4)


begin

Screen.Cursor := crHourglass;

if Query1.Active then Query1.Close;

Query1.DatabaseName := strAlias; {set the alias the query poitns to}

Query1.SQL.clear; { empty existing SQL in the query }

Query1.SQL.Add(strQuery); { add query string to query object }

Query1.Active := True; { try to run the query }

Screen.Cursor := crDefault;　

if Query1.Active then

begin

{ If the query didn't return any records, there's no point in

displaying the form. In that event, raise an exception. }

if Query1.RecordCount < 1 then

raise Exception.create('No records matched your criteria. 

Please try again.' );

{ write a message to the browse form's status line }

if strField = '' then

Panel3.Caption := 'Now showing all records from ' + strTable 

+ '...'

else

Panel3.Caption := 'Now showing '+ strTable +' where '+ strField

+' contains values equal to '+ strValue + '...';　

{ show the form }

ShowModal;

end;

end;

finally

frmQuery.Free;

end;

end;

end.

unit RSLTFORM;

interface　

uses

SysUtils, Windows, Messages, Classes, Graphics, Controls, StdCtrls, DB,

Forms, DBCtrls, DBGrids, DBTables, Buttons, Grids, ExtCtrls, Dialogs;

type

TResultForm = class(TForm)

DBGrid1: TDBGrid;

DBNavigator: TDBNavigator;

Panel1: TPanel;

DataSource1: TDataSource;

Panel2: TPanel;

Panel3: TPanel;

Query1: TQuery;

SpeedButton2: TSpeedButton;

Panel4: TPanel;

SpeedButton1: TSpeedButton;

procedure SpeedButton1Click(Sender: TObject);

procedure SpeedButton2Click(Sender: TObject);

end;

var

ResultForm: TResultForm;

implementation

{$R *.DFM}

procedure TResultForm.SpeedButton1Click(Sender: TObject);

begin

Close;

end;

procedure TResultForm.SpeedButton2Click(Sender: TObject);

var

strText: string; { Variable to hold display text }

iCounter: Integer; { Loop counter variable }

begin　

{ Build a string containing the query }

strText := '';

for iCounter := 0 to Query1.SQL.Count - 1 do

strText := strText + Query1.SQL[iCounter];

{ Display the query text }　

MessageDlg('The underlying query is: ' + #10 + #10 + strText,

mtInformation, [mbOK], 0 );

end;　

end.