Delphi – project “ctsMgr.exe” raised exception class EDBEngineError with message “unknown database. Alais:..”

bdedelphi

I was running a Delphi(4) exe . It ran well for few seconds, then raised the error

project "ctsMgr.exe" raised exception
class EDBEngineError with message
"unknown database.
Alais:PerDBS". Process stopped. Use Step or
Run to continue.

Does the above error imply that Database named "perDBS " is undefined?
Should I "Step" or "run" to continue?

Regards
-Vas

Best Answer

More likely it means that the alias "PerDBS" exists, but is pointing at a nonexistant DB. Hit run, then fix the alias in BDE Administrator or SQL Explorer, then re-run the application.

If you don't see an alias for PerDBS (in either tool) at all, you'll need to create one.

You don't say which DB the app uses. This article explains how to set up an alias for dBase. But the BDE supports many other DB engines. Others are set up similarly, but have different options.

Related Solutions

Delphi: EReadError with message ‘Property Persistence does Not Exist’

Open the Form in Delphi IDE
Use Alt + F12 to edit the .DFM source
Search the "Persistence" property
Delete the line with "Persistence" property

DFM example:

SomeComponent1 = TSomeComponent
  OtherProperty = OtherValue
  Persistence = True
  AnotherProperty = AnotherValue
end

Also you can use the great DFMCheck 1.4 tool, by Andreas Hausladen. To check any other missing property like that:

http://andy.jgknet.de/blog/?page_id=177

This is most likely caused by the compiled & installed package being out of sync with the actual .pas file. If you have source code then rebuilding the packages will probably fix it.

Mysql – Using parameters with ADO Query (thesql/MyConnector)

I would try adding SQL.BeginUpdate/SQL.EndUpdate around the Adds, otherwise the SQL text will be parsed every time you call "Add".

This is generally a good idea, as ADOQuery.SQL is a TStringList that has an OnChange event that sets the CommandText. SetCommandText text then end up calling TADOCommand.AssignCommandText which does a fair amount of work parsing params, and setting CommandObject.CommandText. Sometimes drivers will fail with partial SQL statements, but this stuff looks OK.

I had a similar problem many years ago - that's why I learnt about this stuff!

procedure TForm1.login();
var
  Qry : TADOQuery;
begin
  Qry := CreateSQL;
  try
    Qry.SQL.BeginUpdate;

    Qry.SQL.Add('SELECT');
    Qry.SQL.Add('  *');
    Qry.SQL.Add('FROM');
    Qry.SQL.Add('  LisenswebUsers');
    Qry.SQL.Add('WHERE UserName = :MyUsername '); // debugger exception here
    Qry.SQL.Add('  AND UserPassword = :MyPassword '); // debugger exception here

    Qry.SQL.EndUpdate;
    Qry.Parameters.ParamByName('MyUsername').value := txtLogin.text;
    Qry.Parameters.ParamByName('MyPassword').value := strmd5(txtPassword.text);
    Qry.Open;

    if Qry.Recordcount <> 1 then
    begin
      lblLoggedinAs.Text := format('Du er logget inn som: %s (%s)',[FieldByName('Username').AsString,FieldByName('UserEmailaddress').AsString]);
      MainPageControl.ActivePageIndex := 1;
    end
    else
    begin
      txtPassword.Text := '';
      txtPassword.SetFocus;
    end;
  finally
    Qry.Free;
  end;
end;

BTW, the nested withs are really ugly (let the holy war begin)

I will sometimes use with, but would never nest three levels! If you are, at least reduce the scope of with SQL so it ends before with Parameters.

Best Answer

Related Solutions

Delphi: EReadError with message ‘Property Persistence does Not Exist’

Mysql – Using parameters with ADO Query (thesql/MyConnector)

Related Topic