关于数据库连接的问题，在线等待

Question

procedure TForm1.ADOConnection1WillConnect(Connection: TADOConnection;
  var ConnectionString, UserID, Password: WideString;
  var ConnectOptions: TConnectOption; var EventStatus: TEventStatus);
var
  filename:string;
begin
  filename:= ExtractFilePath(Application.ExeName)+'db1.mdb';
  ConnectionString:=connectstr1+filename+connectstr2;
     //connectstr1，2是接数据库的字符串
   // useriD:='';
 // password:='';end;
在这段代码调试到 ConnectionString:=connectstr1+filename;后，总是显示以下的提示：‘variable connectionstring inaccssible here to due to ooptimization;

Answer 1

先静态设置ConnectionString,再与动态生成的结果比较。

Answer 2

采用何种连接方式没有填
比如   JET OLE DB 4。0

Answer 3

为sql server2000
    FileName := ExtractFilePath(application.ExeName)+'\Sys.ini';
    GetPrivateProfileString('DBMS','username','',username,20,pchar(filename));
    GetPrivateProfileString('DBMS','servername','',servername,20,pchar(filename));
    GetPrivateProfileString('ver','ver','',version1,20,pchar(filename));
    ConnectionString:='Provider=SQLOLEDB.1;Persist Security Info=False'+
                      ';User ID='+username+';Password=12345'+';Initial Catalog=manage'+
                      ';Data Source='+servername+';';
    ADOConnection1.ConnectionString:=ConnectionString;
    ADOConnection1.LoginPrompt:=False;