使用Delphi创建新的ODBC用户DSN

Question

我正在尝试使用以下代码在ODBC数据源管理器中在用户DSN中创建一个新条目:

procedure TForm1.FormCreate(Sender: TObject);
var strAttributes: string;
    wideChars   : array[0..1000] of WideChar;
     pfErrorCode: DWORD;
     errMsg: PChar;

begin
 strAttributes := 'DSN=' + 'example_DSN' + Chr(0);
    strAttributes := strAttributes + 'DESCRIPTION=' + 'description' + Chr(0);
    strAttributes := strAttributes + 'SERVER=' + 'testserver' + Chr(0);
    strAttributes := strAttributes + 'DATABASE=' + 'somedatabase' + Chr(0);

  StringToWideChar(strAttributes, wideChars, 12);
  if not SqlConfigDataSource(0, ODBC_ADD_DSN, 'SQL Server', wideChars) then
  begin
    errMsg := AllocMem(SQL_MAX_MESSAGE_LENGTH);
    SQLInstallerError(1, @pfErrorCode, errMsg, SQL_MAX_MESSAGE_LENGTH, nil);
    MessageBox(0, errMsg, PChar('Add System DSN Error #' + IntToStr(pfErrorCode)), 0);
    FreeMem(errMsg);
  end;
end;

但是SqlConfigDataSource部分不能完成这项工作,并且返回的错误也不是无法解决的.它不是数字,也不是错误的描述.任何人都可以在我犯错的地方帮助我吗？谢谢

Answer 1

可能是您的错误甚至错误集都是ODBC标头的错误翻译,然后可能会用于非Unicode或Unicode Delphi版本.例如:

• 对于Unicode Delphi,你需要使用XxxW(UTF16)函数ODBCCP32.DLL,而不是Xxx(ANSI)函数;
• 对于非Unicode Delphi而不是Xxx函数.然后wideChars应该定义为array[..] of Char;
• SqlConfigDataSource可以定义为XxxW与PAnsiChar;
• 等等

我想向你展示这个想法,因为没有完整的资料我只能推测.然后你有可疑的电话StringToWideChar(strAttributes, wideChars, 12);.strAttributes值远远超过12个字符.

以下代码在Delphi XE2中运行良好:

type
  SQLHWnd = LongWord;
  SQLChar = Char;
  PSQLChar = ^SQLChar;
  SQLBOOL = WordBool;
  UDword = LongInt;
  PUDword = ^UDword;
  SQLSmallint = Smallint;
  SQLReturn = SQLSmallint;

const
  SQL_MAX_MESSAGE_LENGTH = 4096;

  ODBC_ADD_DSN     = 1;         // Add data source
  ODBC_CONFIG_DSN  = 2;         // Configure (edit) data source
  ODBC_REMOVE_DSN  = 3;         // Remove data source

  ODBC_ADD_SYS_DSN    = 4;          // add a system DSN
  ODBC_CONFIG_SYS_DSN   = 5;        // Configure a system DSN
  ODBC_REMOVE_SYS_DSN   = 6;        // remove a system DSN
  ODBC_REMOVE_DEFAULT_DSN   = 7;    // remove the default DSN

function SQLConfigDataSource (
    hwndParent:     SQLHWnd;
    fRequest:       WORD;
    lpszDriver:     PChar;
    lpszAttributes: PChar
  ): SQLBOOL; {$IFDEF MSWINDOWS} stdcall {$ELSE} cdecl {$ENDIF};
  external 'odbccp32.dll' name 'SQLConfigDataSourceW';

function SQLInstallerError (
    iError:           WORD;
    pfErrorCode:      PUDword;
    lpszErrorMsg:     PChar;
    cbErrorMsgMax:    WORD;
    pcbErrorMsg:      PWORD
  ): SQLReturn; {$IFDEF MSWINDOWS} stdcall {$ELSE} cdecl {$ENDIF};
  external 'odbccp32.dll' name 'SQLInstallerErrorW';

procedure TForm616.Button1Click(Sender: TObject);
var
  strAttributes: string;
  pfErrorCode: UDword;
  errMsg: PChar;
begin
  strAttributes := 'DSN=' + 'example_DSN' + Chr(0);
  strAttributes := strAttributes + 'DESCRIPTION=' + 'description' + Chr(0);
  strAttributes := strAttributes + 'SERVER=' + 'testserver' + Chr(0);
  strAttributes := strAttributes + 'DATABASE=' + 'somedatabase' + Chr(0);
  if not SqlConfigDataSource(0, ODBC_ADD_DSN, 'SQL Server', PChar(strAttributes)) then begin
    errMsg := AllocMem(SQL_MAX_MESSAGE_LENGTH);
    SQLInstallerError(1, @pfErrorCode, errMsg, SQL_MAX_MESSAGE_LENGTH, nil);
    MessageBox(0, errMsg, PChar('Add System DSN Error #' + IntToStr(pfErrorCode)), 0);
    FreeMem(errMsg);
  end;
end;