When I run my program and press one of my login buttons it says missing connection or connection string
The connection string is already there
procedure TFmLogin.BtnLogin2Click(Sender: TObject);
begin
ADOUser.ConnectionString:=Connstr;
ADOUser.TableName:='TblUser';
ADOUser.Open;
if ADOUser.Locate('Username', EdUsename.Text,[]) then
begin
if EdPassword.Text=ADOUser['Pword'] then
begin
if ADOUser['AdminLevel']>=0 then
begin
FmBrowse.Delete;
Close
end
else
showmessage('password invalid.');
End;
end
else
Begin
showmessage('Username invalid.');
end;
Close;
end;
I can't find anywhere in this procedure that it should be looking for a connection string and wondered if anyone could help me figure out where I've gone wrong
Usually in ADO u have to write the full path of your database.
and yours is
Const ConnStr='Provider=Microsoft.Jet.OLEDB.4.0;Data Source=cardb.mdb;Persist Security Info=False';
try to change the Source=cardb.mdb; to Source=[[full path]]\cardb.mdb;
Hope this works.
Path doesnt matter as long as the DB is in the same place as where is executable is being compiled. If not then yes you need to put in the full path as Dreamer64 suggested +
His connecting before auth, I think he is missing the username his connections string and the passwords not being saved on the component. Try :
Const ConnStr='Provider=Microsoft.Jet.OLEDB.4.0;'+
'Persist Security Info=False;'+
'User ID=[yourdbusername];'+
'Initial Catalog=[yourtablename];'+
'Data Source=cardb.mdb;';
Now on your ado component right click it and edit string, next to that build string, the first tab should present you with the path username and password fill in the password and test connection, if test succeeds, you are good to go.
Related
I want to connect to a SQL Server using ZEOS components under Windows, compiler is LAZARUS.
Here is my function:
procedure ConnecttoDatabase(Servername, Databasename: String;
aConnection: TZConnection); overload;
var
DatabaseStr: String;
begin
aConnection.Connected := False;
aConnection.Database := 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=' + Databasename +'.mdb;Persist Security Info=False';
aConnection.HostName := Servername;
aConnection.Protocol := 'ado';
aConnection.Connected := True;
end;
Execute this function I get an "EOLE Exception" error, I need help on the correct connection string
As mentioned by mirtheil your connection string is wrong.
An easy way to get a good connection string is by using an UDL file.
Simply create a text file with extension .UDL and then doubleclick on it from explorer. Now you get a window where you can choose from all installed drivers and choose/enter the values you need. You can click on test connectionto see if it works.
Once you get it working there, open this file in notepad and there will be a complete connectionstring.
Your connection string is wrong. With it, you're trying to use the Jet OLEDB provider. If you are truly connecting to a Microsoft SQL Server database, you should be using the SQLOLEDB or SQL Native Client to connect. You can use the MS SQL Server section on Connectionstrings.com to get a proper connection string.
i would like to know whether a user inputs the correct combination of Domain, User and Password for his Active Directory user.
I tried to make a very simple program that is not able to connect but by reading the error message i can know if the user/password is correct.
This is trick based (the logic is on reading the Exception message), anyway i testd this prototype on 2 servers and i noticed that the excpetion messages change from server to server so this is not reliable.
uses adshlp, ActiveDs_TLB;
// 3 TEdit and a TButton
procedure TForm4.Button1Click(Sender: TObject);
Var
aUser : IAdsUser;
pDomain, pUser, pPassword : string;
myResult : HRESULT;
Counter: integer;
begin
pDomain := edtDomain.Text;
pUser:= edtUser.Text;
pPassword := edtPwd.Text;
Counter := GetTickCount;
Try
myResult := ADsOpenObject(Format('LDAP://%s',[pDomain]),Format('%s\%s',[pDomain,pUser]),pPassword,
ADS_READONLY_SERVER,
IAdsUser,aUser);
except
On E : EOleException do
begin
if (GetTickCount - Counter > 3000) then ShowMessage ('Problem with connection') else
if Pos('password',E.Message) > 0 then ShowMessage ('wrong username or password') else
if Pos('server',E.Message) > 0 then ShowMessage ('Connected') else
ShowMessage('Unhandled case');
memLog.Lines.Add(E.Message);
end;
end
end;
The reason why i set "Connected" if the message contain "server" is that on my
local machine (on my company ldap server in fact) in case all is fine (domain, user and password) the server replies "The server requires a safer authentication", so the "server" word is in there, while in other cases it says "wrong user or password". SInce this must work on itlian and english servers i set "server" and "pasword" as reliable words. Anyway i tested on another server that gives differente errors.
I started from a reply to this question to do the above.
How can i check if the user set the correct password or not in a more reliable way using a similar technique?
UPDATE (found solution)
Thanks to the replies i managed to write this function that does what i need. It seems quite reliable up to now, I write here to share, hoping it can help others:
// This function returns True if the provided parameters are correct
// login credentials for a user in the specified Domain
// From empirical tests it seems reliable
function UserCanLogin(aDomain, aUser, aPassword: string): Boolean;
var
hToken: THandle;
begin
Result := False;
if (LogonUser(pChar(aUser), pChar(aDomain), pChar(aPassword), LOGON32_LOGON_INTERACTIVE,
LOGON32_PROVIDER_DEFAULT, hToken)) then
begin
CloseHandle(hToken);
Result := True;
end;
end;
You need to check the error code that ADsOpenObject returns. do not base your error checking on the returned exception messages.
if the function succeeded it will return S_OK, otherwise you need to refer to ADSI Error Codes, specifically, the LDAP error codes for ADSI
When an LDAP server generates an error and passes the error to the
client, the error is then translated into a string by the LDAP client.
This method is similar to Win32 error codes for ADSI. In this example,
the client error code is the WIN32 error 0x80072020.
To Determine the LDAP error codes for ADSI
Drop the 8007 from the WIN32 error code. In the example, the remaining hex value is 2020.
Convert the remaining hex value to a decimal value. In the example, the remaining hex value 2020 converts to the decimal value
8224.
Search in the WinError.h file for the definition of the decimal value. In the example, 8224L corresponds to the error
ERROR_DS_OPERATIONS_ERROR.
Replace the prefix ERROR_DS with LDAP_. In the example, the new definition is LDAP_OPERATIONS_ERROR.
Search in the Winldap.h file for the value of the LDAP error definition. In the example, the value of LDAP_OPERATIONS_ERROR in
the Winldap.h file is 0x01.
For a 0x8007052e result (0x052e = 1326) for example you will get ERROR_LOGON_FAILURE
From your comment:
Since the function always raises an exception i am not able to read
the code
You are getting an EOleException because your ADsOpenObject function is defined with safecall calling convention. while other implementations might be using stdcall. when using safecall Delphi will raise an EOleException and the HResult will be reflected in the EOleException.ErrorCode, otherwise (stdcall) will not raise an exception and the HResult will be returned by the ADsOpenObject function.
i would like to know whether a user inputs the correct combination of
Domain, User and Password for his Active Directory user.
You can use LogonUser function to validate user login e.g. :
if (LogonUser(pChar(_Username), pChar(_ADServer), pChar(_Password), LOGON32_LOGON_INTERACTIVE,
LOGON32_PROVIDER_DEFAULT, hToken)) then
begin
CloseHandle(hToken);
//...
//DoSomething
end
else raise Exception.Create(SysErrorMessage(GetLastError));
Note: You must use LogonUser within a domain machine to be able to use the domain login or the function will always return The user name or password is incorrect
The alternative is using TLDAPSend e.g. :
function _IsAuthenticated(const lpszUsername, lpszDomain, lpszPassword: string): Boolean;
var
LDAP : TLDAPSend;
begin
Result := False;
if ( (Length(lpszUsername) = 0) or (Length(lpszPassword) = 0) )then Exit;
LDAP := TLDAPSend.Create;
try
LDAP.TargetHost := lpszDomain;
LDAP.TargetPort := '389';
....
LDAP.UserName := lpszUsername + #64 + lpszDomain;;
LDAP.Password := lpszPassword;
Result := LDAP.Login;
finally
LDAP.Free;
end;
end;
How can i check if the user set the correct password or not in a more
reliable way using a similar technique?
Try to use FormatMessage function
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER or FORMAT_MESSAGE_FROM_SYSTEM,
nil,
myResult,
LANG_ENGLISH or SUBLANG_ENGLISH_US,
lpMsg,
0,
nil);
MessageBox(0, lpMsg, 'Msg', 0);
I get (HRESULT) 0x8007052e (2147943726) "unknown user name or bad password" when I use a wrong password. And there is no EOleException, try:
hr := ADsOpenObject('LDAP://'+ ADomain + '/OU=Domain Controllers,' + APath,
AUser, APwd,
ADS_SECURE_AUTHENTICATION or ADS_READONLY_SERVER,
IID_IADs, pObject);
if (hr=HRESULT(2147943726)) then ShowMessage ('wrong username or password')
Hello fellow StackOverflowers,
Currently I'm facing a situation where it seems that there is a maximum length for the Database property of a TSQLConnection object in Delphi.
When I open the connection to my database I get the following error when I use a rather long (154 chars) database name:
dbExpress Error: [0x0015]: Connection failed
SQL Server Error: unrecognized database parameter block
wrong version of database parameter block
When I relocate my database file to another location (and with that reduce the length of the path) it will connect to the database.
I am currently using the Object Inspector to set the connection properties of the TSQLConnection object.
Basically, my question comes down to this:
Does a TSQLConnection have a maximum length for the values set in the Params property? And if so, what is the maximum length of these values?
Update
I've found two ways to open a copy of Employee.Gdb in a folder with a 160-character name ('abcdefghij0123456789' x 8).
What I did firstly was to edit the DBXConnections.Ini file and changed the Database parameter in the [IBConnection] section to read
Database=localhost:D:\abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890\employee.gdb
Then, I can successfully connect to it, open the Employee.Gdb and make changes to the Customer table. I have verified the changes in IBConsole just in case the copy of Employee.Gdb wasn't the one I assumed it was.
Subsequently, I've found that I can create and open the db in code using Delphi Seattle and Interbase XE7, as follows:
function LongPath : String;
begin
Result := 'D:\' + DupeString('abcdefghij0123456789', 8);
end;
function LongDBName : String;
begin
Result := LongPath + '\Employee.Gdb';
end;
procedure TForm1.OpenDB;
var
Ini : TMemIniFile;
const
scDBXConIni = 'C:\Users\Public\Documents\Embarcadero\Studio\dbExpress\17.0\dbxconnections.ini';
scSourceDB = 'D:\Delphi\Databases\Interbase\Employee.Gdb';
begin
Ini := TMemIniFile.Create(scDBXConIni);
try
// First, blank out the Database value in the IBConnection section
// of DBXConnections.Ini
Ini.WriteString('IBConnection', 'Database', '');
Ini.UpdateFile;
// Next, create the long-named directory and copy Employee.Gdb to it
if not DirectoryExists(LongPath) then
MkDir(LongPath);
Assert(CopyFile(PChar(scSourceDB), PChar(LongDBName), False));
// Set LoadParamsOnConnect to False so that the SqlConnection uses
// the value of the Database we are about to give it
SqlConnection1.LoadParamsOnConnect := False;
SqlConnection1.Params.Values['Database'] := LongDBName;
SqlConnection1.Connected := True;
// Open the CDS to view the data
CDS1.Open;
finally
Ini.Free;
end;
end;
The critical step in doing it this way is setting LoadParamsOnConnect to False, which I confess I'd overlooked in earlier attempts to get this code to work.
I've got some earlier versions of Delphi on this machine, so if you're not using Seattle and the above code doesn't work for you, tell me which one you are using and I'll see if I can try that.
**[Original answer]
Actually, I think that this may be an error occurring in one of the DBX DLLs.
I created a folder with a 160-character name, then copied the demo Employee.Gdb database into it. Interbase XE7's IBConsole can open the db without error. So could a small test project contructed with IBX components in Delphi Seattle.
However, with an equivalent DBX project, when I use the code below
procedure TForm1.Button1Click(Sender: TObject);
begin
SqlConnection1.Params.Values['database'] := 'D:\abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890abcdefghij01234567890\employee.gdb';
SqlConnection1.Connected := True;
end;
I get an error in
procedure TDBXDynalinkConnection.DerivedOpen;
var
Count: TInt32;
Names: TWideStringArray;
Values: TWideStringArray;
IsolationLevel: Longint;
DBXError: TDBXErrorCode;
begin
Count := FConnectionProperties.Properties.Count;
FConnectionProperties.GetLists(Names, Values);
CheckResult(FMethodTable.FDBXConnection_Connect(FConnectionHandle, Count, Names, Values));
DBXError := FMethodTable.FDBXConnection_GetIsolation(FConnectionHandle, IsolationLevel);
'I/O error for file "database.gdb"
Error while trying to open file
The operation completed successfully'
and the Database param of the SqlConnection is left at the value 'Database.Gdb', which is not the value I specified, of course, nor was it the value specified in the params in the IDE, which was 'd:\delphi\databases\interbase\employee.gdb'.
I wondered if I could work around this problem by SUBSTing a drive to the 'abcdefg ...' path. I tried that and opening the database as "x:\employee.gdb" , but I get the same error in my DBX app, and also IBConsole cannot access the db either.
I think you need a shorter physical path!**
This is related to MSSql Server:
As a general guideline, long path names greater than 160 characters
might cause problems.
from Microsoft TechNet - https://technet.microsoft.com/en-us/library/ms165768(v=sql.105).aspx
I was using an example from here :
establishing connection
Did it this way :
procedure TDataModule2.DataModuleCreate(Sender: TObject);
begin
with FDGUIxLoginDialog1.VisibleItems do begin
Clear;
Add('Server=Strežnik');
Add('User_name=Uporabnik');
Add('Password=Geslo');
Add('Database=Baza');
end;
try
FDConnection1.Connected := True;
except
on E: EAbort do
application.terminate; // user pressed Cancel button in Login dialog
on E:EFDDBEngineException do
case E.Kind of
ekUserPwdInvalid: ; // user name or password are incorrect
//ekUserPwdExpired: ; // user password is expired
ekServerGone: ; // DBMS is not accessible due to some reason
else
// other issues
end;
end;
end;
However, application will not terminate after hitting cancel in the login dialog but shows my main form. What should I do to correct this ?
Also, how can I flash a message if the password was wrong, in this scenario ?
Firedac is connecting to SQL Server.
ps
Even this will not work :
.....
except
on E: EFDDBEngineException do
if E.Kind = ekUserPwdInvalid then
begin
ShowMessage('A user name or a password are invalid');
Abort;
end;
An application usually quits by closing its main form.
You should never let an application quit by issuing an exception; it's bad form.
EAbort is not an exception that gets issued by the login dialog. In fact under normal circumstances te login dialog will not issue any exception.
If the user presses Cancel then the connection will not get ehm.. connected, you can test that.
Here's a list of all the errors TFDConnection can generate.
The following code should work:
type
TAction = (aSuccess, aGiveup, aWrongPassword, aPasswordExpired);
procedure TDataModule2.DataModuleCreate(Sender: TObject);
var
VI: TStrings;
WhatToDo: TAction;
begin
WhatToDo:= aSuccess;
VI:= FDGUIxLoginDialog1.VisibleItems;
VI.Clear;
VI.Add('Server=Strežnik');
VI.Add('User_name=Uporabnik');
VI.Add('Password=Geslo');
VI.Add('Database=Baza');
try
FDConnection1.Connected := True;
except
on E:EFDDBEngineException do case E.Kind of
ekUserPwdInvalid: WhatToDo:= aWrongPassword;
ekUserPwdExpired: WhatToDo:= aPasswordExpired;
else WhatToDo:= aGiveUp;
end; {case}
end;
if Not(FDConnection1.Connected) then WhatToDo:= aGiveUp;
case Action of
aWrongPassword: begin
ShowMessage('You've entered a wrong username or password please try again');
DataModuleCreate(Sender);
Action:= aSuccess;
end;
aPasswordExpired: ShowMessage('You password has expired, please request a new one from the PHB');
end;
if Action <> aSuccess then Application.Terminate;
end;
Comments about coding style
Do not use with. With is evil use a temporary variable instead and use that to reference the nested variable(s).
Terminating on an error without issuing an error is really silly.
No user is going to be happy having an application die on them without any explanation why.
You should never terminate on a wrong password or username.
As least give the user the change to try again 3 or 4 times.
If he doesn't get it right by then issue the "wrong username or password" error message and quit.
Never tell the user which (username or password) is wrong, an attacker can use that to generate a list of usernames.
I'm working to an application with a login form at the start-up.
Until user is writing the login data, I would like to connect discreetly to the SQL server.
The problem is that, when I have a slow connection or a wrong path to the server, the application is looking for the server or trying to connect and in this time the application is not responding.
For connection I use this procedure:
//-- SQL connect --//
procedure TSql.Connect;
var
DriverId: String;
i: Byte;
begin
try
Screen.Cursor:=crAppStart;
//connection DriverName
DriverId:=Server[FServerType].DriverId;
FConnection.DriverName:=DriverId;
//connection Params
FConnection.Params.Clear;
FConnection.Params.Add('DriverID='+DriverId); //mandatory
if FConnString.Count>0 then
for i := 0 to FConnString.Count-1 do FConnection.Params.Add(FConnString.Strings[i]);
try
FConnection.Open;
FQuery.Connection:=FConnection;
except
on E : Exception do ShowError(_('Connection could not be established!'),E);
end;
finally
Screen.Cursor:=crdefault;
end;
end;
Please help me with some suggestion about how this can be done. I've read about threads and Application.ProcessMessages but I did not succeed to make it work smoothly.
Create a new thread, and do everything you need on it, that will not hang the main form and the user will not see anything you can see simillar functionality here