处理期间如何查看查询执行进度? [英] How to see progress of query execution during handle?

问题描述

我在 delphi 中使用了以下代码作为句柄:

I used the following code in delphi for handle :

procedure TForm1.ADOQuery1FetchProgress(DataSet: TCustomADODataSet; Progress,

  MaxProgress: Integer; var EventStatus: TEventStatus);

begin

    Progressbar1.Visible:=true;

    Progressbar1.Max:=MaxProgress;

    Progressbar1.Ppsitian:=Progress;

    Progressbar1.Visible:=false;

end;

但是....我看不到任何效果(这段代码没有执行)

but.... I can't see any effect (this code doesn't execute)

我想在用户单击数据库中的 ٍُSEARCH 按钮时显示查询执行的进度，从开始到完成过滤器在进度条中.

I want to show progress of query execution during when the user clicked a button for ٍُSEARCH in database from begining to finish filter in progressbar.

按钮点击代码:

with ADOQuery1 do

begin

SQL.Clear;

SQL.Add('select * from tbl1 where id = '+Edit1.Text);

Open;

end;

但我在进度条中没有任何突变，好像没有在 OnFetchProgress 事件中编写任何代码.

but i don't any mutation in the progress bar , as though don't write any code in OnFetchProgress event.

我代表你了吗?

推荐答案

你必须设置属性 ExecuteOptions 到 eoAsyncFetch 在调用 open 过程之前

you must set property ExecuteOptions to eoAsyncFetch before to call the open procedure

检查此示例

with ADOQuery1 do
begin
 SQL.Clear;
 SQL.Add('select * from tbl1 where id = '+Edit1.Text);
 ExecuteOptions:=[eoAsyncFetch];
 Open;
end;


procedure TForm1.ADOQuery1FetchProgress(DataSet: TCustomADODataSet; Progress,
  MaxProgress: Integer; var EventStatus: TEventStatus);
begin
  ProgressBar1.Max      :=MaxProgress;
  ProgressBar1.Position :=Progress;
  Application.ProcessMessages;
end;

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