可编辑的DBGrid？

Question

我是Delphi的初学者，我需要帮助解决以下问题。我必须在我的表单上实现一个可编辑的DBGrid。DBGrid显示连接3个表的查询的结果。我设法使DBGrid可编辑，但编辑对数据库没有任何影响。我可以在DBGrid中插入、编辑或删除行，但这些更改不会保存到数据库中。我有以下设置：

Query2.DatabaseName=Test
Query2.SQL=SELECT cd.hourstart, cd.hourfinish, o.objname, cd."work", cd.worktime  
           FROM Card c JOIN CardDetail cd ON c.N=cd.card  
           JOIN objects o ON cd.project=o.N  
           WHERE c.worker=5 AND c.data=CONVERT(DATE, GETDATE())
Query2.UpdateObject=UpdateSQL2  
Query2.CachedUpdates=True  
Query2.RequestLive=True

UpdateSQL2.DeleteSQL=delete from CardDetail  
                     where hourstart = :OLD_houerstart and  
                     hourfinish = :OLD_houerfinish and  
                     work = :OLD_work and  
                     worktime = :OLD_worktime
UpdateSQL2.InsertSQL=...  
UpdateSQL2.ModifySQL=...  

DataSource2.DataSet=Query2  
DBGrid2.DataSource=DataSource2 

我可能错过了什么，但我不知道是什么。任何帮助都将不胜感激！

Answer 1

据说您需要几个UpdateSQL对象，每个表http://docwiki.embarcadero.com/RADStudio/XE3/en/Using_Multiple_Update_Objects_Index一个

这些对象中的每个对象都应该绑定基本TDataSet，以便引用普通数据。http://docwiki.embarcadero.com/Libraries/en/Bde.DBTables.TDataSetUpdateObject.DataSet

据称，在不同的对象上调用ApplyUpdates/Commit/Commit objects的顺序应该是正确的。http://docwiki.embarcadero.com/RADStudio/en/Applying_Cached_Updates_with_Dataset_Component_Methods

PS。BDE已被弃用，并且与最新的Windows和最新的数据库服务器兼容性很差。

Answer 2

// Have a look at the below code, it uses an AdoCommand
procedure DoSomething(DataSet: TDataSet);
var
  ADOCommand : TADOCommand;
begin
  ADOCommand:=TADOCommand.Create(nil);
  try
  try
    ADOCommand.Connection:=Conn;
    ADOCommand.Parameters.Clear;
    Conn.BeginTrans;
    if dataset.State = dsinsert then
    begin
      ADOCommand.CommandText := //Your insert statement
      ADOCommand.ParamCheck:=False;
      ADOCommand.Execute;
    end
    else
    if DataSet.State = dsEdit then
    begin
      ADOCommand.CommandText := //Your edit statement
      ADOCommand.ParamCheck:=False;
      ADOCommand.Execute;
    end
    else
    Begin
      ADOCommand.CommandText := //Your delete statement
      ADOCommand.ParamCheck:=False;
      ADOCommand.Execute;
    End;
    Conn.CommitTrans;
  except
    on E : Exception do
    begin
      Conn.RollbackTrans;
      MessageDlg('An exception occured, Error Class: ' + E.ClassName         +#13+                      'ErrorMessage: '+ E.Message , mtError, [mbOK], 0);
      Abort;
    end;
  end;
  finally
    ADOCommand.Free;
  end;
end;