Question

Normal Query vs. ADOQuery

Asked by: barlet

Hi experts,

I have the following code and it is working fine with normal Query component from delphi

  Query1.ParamByName('username').AsString:=Edit1.Text;
  Query1.ParamByName('password').AsString:=Edit2.Text;

but when I want to use ADOQuery like this:
  ADOQuery1.ParamByName('username').AsString:=Edit1.Text;
  ADOQuery1.ParamByName('password').AsString:=Edit2.Text;

the ParamByName and AsString appears to be incorrect...

any possible way to make this work?

Thanks

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Asked On
2009-08-20 at 00:44:31ID24667350
Tags

Delphi Programming

,

ADOQuery

Topic

Delphi Database

Participating Experts
3
Points
250
Comments
9

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Answers

 

by: gtworekPosted on 2009-08-20 at 00:55:45ID: 25140083

Do you need to call SQL stored procedure? In such case you should use TADOStoredProc.

 

by: bokistPosted on 2009-08-20 at 02:24:48ID: 25140521

in case of ADOQuery instead of
  Query1.ParamByName('username').AsString:=Edit1.Text;
you must use
  ADOQuery1.Parameters.ParamByName('username').Value := Edit1.Text;
Steve...

 

by: barletPosted on 2009-08-20 at 12:21:41ID: 25146093

bokist,

I like your comment...  I have now something like the following

  ADOQuery1.Close;
  ADOQuery1.SQL.Clear;
  ADOQuery1.SQL.Add('select count(*) compare from smsystem.users T ');
  ADOQuery1.SQL.Add('where (T.username =:username) ');
  ADOQuery1.SQL.Add('and (T.password =:password) ');
  ADOQuery1.Parameters.ParamByName('username').Value:=Edit1.Text;
  ADOQuery1.Parameters.ParamByName('password').Value:=Edit2.Text;
  ADOQuery1.Open;
Label2.Caption:=ADOQuery1.FieldByName('compare').AsString;


but Label2 always shows me 1. If the password is wrong Label2 should be 0 but its always 1.
why is that?!

 

by: bokistPosted on 2009-08-20 at 21:44:51ID: 25149191

You should do it this way:


  ADOQuery1.Close;
  ADOQuery1.SQL.Clear;
  ADOQuery1.SQL.Add('select username from smsystem.users ');
  ADOQuery1.SQL.Add('where username =:username ');
  ADOQuery1.SQL.Add('    and password  =:password ');
  ADOQuery1.Parameters.ParamByName('username').Value:=Edit1.Text;
  ADOQuery1.Parameters.ParamByName('password').Value:=Edit2.Text;
  ADOQuery1.Open ;
  if EOF  then     // no matching records - something is wrong (username or password)
  else                 // OK - Record found

 

by: barletPosted on 2009-08-21 at 05:11:21ID: 25150931

when I do this:


--  if EOF then Label2.Caption:='0'     // no matching records - something is wrong (username or password)
--  else                 // OK - Record found
--  Label2.Caption:='1';

after the code you wrote above it shows an error that says ( I/O error 6)

Barlet

 

by: Geert_GruwezPosted on 2009-08-21 at 20:32:18ID: 25157297

if you want to know if you have found records, use IsEmpty

if ADOQuery1.IsEmpty then
  // no records ...

 

by: bokistPosted on 2009-08-22 at 15:15:05ID: 25160453

There was a misprint in last line, right way is:

 ADOQuery1.Close;
  ADOQuery1.SQL.Clear;
  ADOQuery1.SQL.Add('select username from smsystem.users ');
  ADOQuery1.SQL.Add('where username =:username ');
  ADOQuery1.SQL.Add('    and password  =:password ');
  ADOQuery1.Parameters.ParamByName('username').Value:=Edit1.Text;
  ADOQuery1.Parameters.ParamByName('password').Value:=Edit2.Text;
  ADOQuery1.Open;
  if ADOQuery1.EOF  then     // no matching records - something is wrong (username or password)
  else                                   // OK - Record found

 

by: barletPosted on 2009-08-23 at 04:39:34ID: 25162242

Thank you bokist

Geert_Gruwez, your post is also right...

 

by: Geert_GruwezPosted on 2009-08-24 at 01:44:28ID: 25166477

barlet, lol,
you can also accept multiple solutions ...

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