通過SQL語句在Delphi中刪除數據庫和adoquery

Question

我想通過SQL語句刪除數據庫，我的代碼是這樣用delphi XE和ADO的數據庫訪問，服務器是MSSQL

aDBConnection.ConnectionString := 'Provider=SQLOLEDB.1;Integrated  

        Security=SSPI;Persist Security Info=False;Initial Catalog=' 
        + DatabaseName + '; Data Source=' + Servername;  

    aDBConnection.Connected := true; 

    aQuery.Connection := aDBConnection; 

    aQuery.add.sql (' drop database ' + DatabaseName); 

    aQuery.Execsql. 

運行許多其他具有這種代碼序列的sql語句是好的，但他拒絕放棄數據庫，因爲聲明「數據庫正在使用」。

猜測，我真的有一個連接到數據庫，但如何做其他的，我需要查詢的SQL發送到服務器...

Answer 1

沒有需要關閉connnection這是真的顯式的，正如TLama所提到的，你需要的只是USE來改變你的連接。也沒有必要關閉數據集，除非它們以打開CursorLocation：= clUseServer;即使更改爲主模塊（Button_ChangeToMasterClick），您將能夠編輯已打開的數據集，但由於CursorLocation爲clUseClient，您甚至可以刪除數據庫。自然掉落後編輯會導致錯誤。

Const 
aDatabaseName='DeleteMeAfterUse'; 

procedure TForm3.ButtonCreateOpen_Click(Sender: TObject); 
var 
    Ads: TAdodataset; 
begin 
    AC.ConnectionString := 'Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=master;Data Source=127.0.0.1'; 
    AC.Connected := true; 
    AC.Execute('Create DataBase ' + aDatabaseName); 
    AC.Execute('Use ' + aDatabaseName); // change connection to 'DeleteMeAfterUse' 
    AC.Execute('Create Table Test (ID int)'); // will be created in DeleteMeAfterUse 
    AC.Execute('Insert into Test Values (1)'); 
    Ads := TAdodataset.Create(self); // Display data on surface 
    // Ads.CursorLocation := clUseServer; ** 
    // ** don't use clUseServer if you want to delete the database without closing the datasets 
    // default is clUseClient 

    With Ads do 
    begin 
    Connection := AC; 
    CommandText := 'Select * from Test'; 
    Active := true; 
    end; 
    DataSource1.DataSet := Ads; // Conected to a DBGrid for editing 
end; 

procedure TForm3.Button_ChangeToMasterClick(Sender: TObject); 
begin 
    AC.Execute('Use master'); // change connection to master , any other database will work too 
end; 

procedure TForm3.Button_DropDatabaseClick(Sender: TObject); 
begin 
    AC.Execute('Drop Database ' + aDatabaseName); 
end;