Help! Login program can't check the credentials!
lazarus / 16-Databases

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workinghard · 2012-04-29 08:53

So i was making a login program (using only 1 parameter, which is the
address) and for reasons that i don't know, it can't do anything
except telling me that the address is not found
Code: [Select]begin
     qcalc.Close;
     qcalc.sql.clear;
     qcalc.sql.add('SELECT * FROM Master WHERE
master.address='+QuotedStr(Address.Text));

    if Qcalc.recordcount = 0 then
    begin
    showmessage('Address not found');
    end 
Where did i mess up? In the master table there are already lots of
addressess, and each one of them doesn't work when tested

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BigChimp · 2012-04-29 09:43

Start reading some documentation as lots of us already asked you to
do.

Try to look up the answer to some question:
How do you execute a query?
Why is it a bad idea to use QuotedStr unless you REALLY know what
you're doing? (Hint: parameters, entering Jim's 12" Steak Knife as
data, or perhaps "The Willows", 12 O'Malley Drive, Maplewood)

Good luck

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workinghard · 2012-04-29 23:09

Following your advice, i changed the code to this:
Code: [Select]     qcalc.Close;
     qcalc.sql.clear;
     qcalc.sql.add('SELECT * FROM Master WHERE
master.address:=Address');
     qcalc.Params.ParamByName('Address').AsString := Address.text;


When I ran the program again, i got the error saying parameter Address
not found...
this error has been present for quite a while now...

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goldenfox · 2012-04-30 03:33

it should be something like

Quoteqcalc.sql.add('SELECT * FROM Master WHERE
master.address=:Address');
qcalc.Params.ParamByName('Address').AsString := Address.text;
Notice the bold =:

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workinghard · 2012-04-30 09:08

Quote from: goldenfox on April 30, 2012, 05:33:33 amit should be
something like

Quoteqcalc.sql.add('SELECT * FROM Master WHERE
master.address=:Address');
qcalc.Params.ParamByName('Address').AsString := Address.text;
Notice the bold =:

I've tried it man, it doesn't work
The code is now:
Code: [Select]begin
     qcalc.Close;
     qcalc.sql.clear;
     qcalc.sql.add('SELECT * FROM master WHERE address=:Address');
     qcalc.Params.ParamByName('Address').AsString := Address.text;

    if QHitung1.recordcount = 0 then
    begin
    showmessage('Address not found!');
    end

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Arbee · 2012-04-30 09:12

Is this the complete code?
I do not see you executing the SQL statement anywhere (via an "open").

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joseme · 2012-04-30 09:14

You should open the query after passing the parameter, the code should
be something like
Code: [Select]begin
     qcalc.Close;
     qcalc.sql.clear;
     qcalc.sql.add('SELECT * FROM master WHERE address=:Address');
     qcalc.Params.ParamByName('Address').AsString := Address.text;
     qcalc.open;

    if qcalc.recordcount = 0 then
    begin
    showmessage('Address not found!');
    end

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workinghard · 2012-04-30 09:24

Following Joseme's advice i've added the qcalc.open code. And now the
code goes like this

Code: [Select]begin
     qcalc.Close;
     qcalc.sql.clear;
     qcalc.sql.add('SELECT * FROM master WHERE address=:Address');
     qcalc.Params.ParamByName('Address').AsString := Address.text;
     qcalc.open;

    if qcalc.recordcount = 0 then
    begin
    showmessage('Address not found!');
    end  
    else

    begin
      Qcalc.Close;
      Qcalc.sql.clear;
      Qcalc.sql.text:='INSERT INTO trmt VALUES (address.text),
CURRENT_TIMESTAMP, 20000, (
SELECT (M.land*RM.landrate)+(M.bldg*RM.bldgrate)
FROM MASTER AS M, Rmnt AS RM
WHERE M.Address := address AND M.Cluster = RM.Cluster)';
      QHitung1.execSQL;
      TransHitung.commit;

      Qcalc.sql.clear;
      Qcalc.sql.text:='
INSERT INTO trair
VALUES (edAddress), CURRENT_TIMESTAMP,(

SELECT M.PemAirTrkr
FROM MASTER AS M
WHERE M.Address:=EdAddress), edMTA, (BAw-BAk)';
      Qcalc.execSQL;
      Transcalc.commit;

      Qcalc.sql.clear;
      Qcalc.sql.text:='UPDATE master SET PemAirTrkr = edMTA WHERE
Alamat = EdAddress';
      Qcalc.ExecSQL;
      Transcalc.Commit;
    end;
end;                     


It still raises the same old error
Do i mess up somewhere else?

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joseme · 2012-04-30 10:05

This is very strange, your code is correct. Can you run this simple
code?
Code: [Select]qCalc.close;
qCalc.Text := 'select * from master';
qCalc.open;
showMessage(qCalc.fieldbyname('Address').Asstring)It should show you
the first address in the table.

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workinghard · 2012-04-30 10:57

I do this:
Code: [Select]procedure TForm3.Button1Click(Sender: TObject);

begin
  qcalc.close;
  qcalc.clear;
  qcalc.add := 'SELECT * FROM Master';
  qcalc.open;

  showmessage(qcalc.fieldbyname('address').asstring) ;
end;

And I get this error:
Quoteunit3.pas(58,12) Error: identifier idents no member "clear"
unit3.pas(59,12) Error: identifier idents no member "add"
unit3.pas(62,22) Error: Identifier not found "qcalc"
unit3.pas(67) Fatal: There were 3 errors compiling module, stopping

And using this syntax:
Code: [Select]qCalc.close;
qCalc.Text := 'select * from master';
qCalc.open;
showMessage(qCalc.fieldbyname('Address').Asstring)

I have this error:
Quoteunit3.pas(58,12) Error: identifier idents no member "text"
unit3.pas(61,22) Error: Identifier not found "qcalc"
unit3.pas(66) Fatal: There were 2 errors compiling module, stopping

Oh, and by using this:
Code: [Select]begin
  qcalc.sql.close;
  qcalc.sql.text := 'SELECT * FROM Master';
  qcalc.sql.open;

  showmessage(qhitung.fieldbyname('address').asstring) ;
end;

This showed up:
Quoteunit3.pas(57,16) Error: identifier idents no member "close"
unit3.pas(59,16) Error: identifier idents no member "open"
unit3.pas(61,22) Error: Identifier not found "qcalc"
unit3.pas(66) Fatal: There were 3 errors compiling module, stopping

Is there anything wrong with my SQL library then?

I use Lazarus 0.9.30.4 with FPC 2.6.0 in Win7 Home Premium x64
Also I installed it in drive D, since the drive C has the older
version and I still need it...

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workinghard · 2012-05-01 15:55

please, anyone?

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dr4cul453xy · 2012-05-16 09:00

Quote from: workinghard on April 30, 2012, 12:57:47 pmI do this:
Code: [Select]procedure TForm3.Button1Click(Sender: TObject);

begin
  qcalc.close;
  qcalc.clear;  // <<<<< THIS ONE
  qcalc.add := 'SELECT * FROM Master'; // <<<<< and THIS ONE
  qcalc.open;

  showmessage(qcalc.fieldbyname('address').asstring) ;
end;
I think you  messed up something (the marked part). the debugger has
already told you what to do
it should be as follow :
Code: [Select]  qcalc.close;
  qcalc.SQL.clear;  // <<<<< CHANGE TO THIS ONE
  qcalc.SQL.add := 'SELECT * FROM Master'; // <<<<< CHANGE TO THIS ONE
  qcalc.open;

please let me know if it still raising error..