[yunqa.de] Re: "Create table with default" problem

Please send your project sources as TProvider and TClientDataSet for
Delphi 5 have a few bugs which make such problems very intricate and
hard to analyze without compiling the sources.

Ralf

On 15.08.2011 17:27, edoardo falzetti wrote:

> Given a Table created with following string:
> 
>  SQL_CREATETABLE_T1 =
>    'CREATE TABLE IF NOT EXISTS T1 ('             + CRLF +
>    '"F1"   TEXT PRIMARY KEY,'                    + CRLF +
>    '"F2"   TEXT,'                                + CRLF +
>    '"F3"   INT DEFAULT 0'                        + CRLF +
>    ')';
> 
> 
> Working with TDISQLite3UniDirQuery + ... + TClientDataset
> 
> 
> If i do the following:
> 
> Case 1
> ======
> 
> cds.open
> cds.insert values : 'K1', 'a'
> ...
> cds.post
> cds.ApplyUpdates
> cds.close
> 
> In the table i find:  'K1', 'a', 0     OK !
> 
> 
> cds.open
> cds.edit 'K1', 'b'
> ...
> cds.post
> cds.ApplyUpdates
> cds.close
> 
> In the table i find:  'K1', 'b', 0     OK !
> 
> 
> Everithing worked fine !
> 
> =========
> 
> But if i do:
> 
> Case 2
> ======
> 
> cds.open
> cds.insert values : 'K1', 'a'
> ...
> cds.post
> cds.ApplyUpdates
> 
> 
> In the table i find:  'K1', 'a', 0     OK !
> 
> 
> 
> cds.edit 'K1', 'b'
> ...
> cds.post
> cds.ApplyUpdates
> 
> ERRORS: 'Record changed by another user'
>         'Unable to find record. No key specified'
> 
> cds.close
> 
> =============
> 
> Looking at the code i found out that in the following function:
> 
> function TDISQLite3UniDirQuery.PSExecuteStatement(
>   const ASql: {$IFDEF COMPILER_10_UP}UnicodeString{$ELSE}AnsiString{$ENDIF};
>   AParams: TParams;
>   AResultSet: Pointer = nil): Integer;
> var
>   Stmt: TDISQLite3Statement;
>   Query: TDISQLite3UniDirQuery;
> begin
>   if Assigned(AResultSet) then
>     begin
>       .......
>     end
>   else
>     begin
>       Stmt := TDISQLite3Statement.Create;
>       try
>         Stmt.Database := Database;
>         Stmt.SQL16 := ASql;               <<<<<<< not well formed
>         Stmt.Active := True;
>         BindParams(Stmt.Handle, AParams);
>         Stmt.Step;
>         Result := Database.Changes;
>       finally
>         Stmt.Free;
>       end;
>     end;
> end;
> 
> 
> the SQL instruction in case 2 is not well formed .
> 
> 
> =======
> Case 1:
> =======
> 
> SQL   : insert into T1 (F1, F2) values (?,    ?)
> 
> Params:                                'K1', 'a'
> 
> Obtained DB row: 'K1', 'a', 0
> 
> ---
> 
> SQL   : update T1 set F2 = ? where F1 = ? and F2 = ? and F3 = ?
> 
> Params:                   'b'          'K1',      'a',        0
> 
> 
> 
> Obtained DB row: 'K1', 'b', 0
> 
> Correct !
> 
> 
> =======
> Case 2:
> =======
> 
> 
> SQL   : insert into T1 (F1, F2) values (?,    ?)
> 
> Params:                                'K1', 'a'
> 
> Obtained DB row: 'K1', 'a', 0
> 
> ---
> 
> SQL   : update T1 set F2 = ? where F1 = ? and F2 = ? and F3 is null
> 
> Params:                   'b'          'K1',      'a'
> 
> 
> 
> WRONG ! F3 is not null but 0 !!!
> 
> =========
> 
> I've got an analogous problem if just after the
>   "insert"-"post"-"ApplyUpdates"
> i do a
>    "delete"-"ApplyUpdates"
> on the same record without closing the cds within the two.
> 
> 
> 
> 
> I hope to have been clear enough.
> 
> Thanks and greetings
> edoardo.
> 
> PS:
> - Delphi version D5
> - Disqlite version ?. Sorry i'm not at work now and cannot check. Anyway it's
> not the last but almost.
> - It's not a big problem to bypass; if it's difficult or long to correct i'll
> eliminate the defaults from the database.
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