On Thu, Jun 19, 2008 at 8:22 AM, Joost van der Sluis <[EMAIL PROTECTED]> wrote:
> Op zaterdag 14-06-2008 om 16:06 uur [tijdzone -0500], schreef Howard Lee > Harkness: > > > However, it doesn't seem to matter what I put in for nbDelete. I > > always get the error "There are no fields found to generate the > > where-clause" if I do ApplyUpdates for nbDelete. If I put nothing in > > there, the field appears to be deleted, but it is still in the table, > > and comes back to the grid when I press "refresh". > > Does your table has a primary key? And do you have set the > 'UsePrimaryKeyAsKey' property to true? Yes, and yes. See the code that I posted at the beginning of the thread -- if you see a problem with the code , please tell me what I'm doing wrong, or not doing right. There is definitely something wrong with it, because it doesn't work. If I left something out, tell me and I can just zip up the whole project and email it to you. > > > sqldb tries to create an delete-query for you, but to do that it has to > indentify the record that should be deleted. Normally it uses the > primary key for that. If there is no primary key, you have to tell it > which fields should be included as a 'key'. (ie: be a part of the > where-statement in the delete query: 'delect from table where ...) Things would be a lot easier for me if only I could find a working example of a small database program using MySQL and Lazarus. I've found a few examples, but I have been unable to make any of them work. Currently, I'm about to download the latest Lazarus/FPC versions to see if something magically works, but it seems to me that I really ought be able to get a trivial program like the one I posted at the beginning of the thread to work with minimal effort. Here again is the code that I posted in the first part of the thread: To start with, here's a sample database setup: CREATE TABLE IF NOT EXISTS ZIPCODE ( ZIPID INT NOT NULL AUTO_INCREMENT, ZIP VARCHAR(5) NOT NULL, ZIPEXT VARCHAR(4), CITY VARCHAR(40), STATE VARCHAR(2), PRIMARY KEY(ZIPID) -- YES! there is a primary key! ); INSERT INTO ZIPCODE (ZIP,ZIPEXT,CITY,STATE) VALUES ('01814',NULL,'Lawrence','MA') ,('13502',NULL,'Utica','NY') ,('22030',NULL,'Fairfax','VA') ,('27030',NULL,'Mt. Airy','NC') ,('27103',NULL,'Winston-Salem','NC') ,('27104',NULL,'Winston-salem','NC') ,('27106',NULL,'Winston-Salem','NC') I started up Lazarus, created an application, and put a DBGrid, DBNavigator, a MySQL50Connection, an SQLTransaction, an SQLQuery, and a DataSource components on it. Here is the Form File: object Form1: TForm1 Left = 307 Height = 300 Top = 180 Width = 602 HorzScrollBar.Page = 601 VertScrollBar.Page = 299 ActiveControl = DBGrid1 Caption = 'Form1' ClientHeight = 300 ClientWidth = 602 Position = poDesktopCenter object DBGrid1: TDBGrid Left = 24 Height = 201 Top = 32 Width = 560 DataSource = Datasource1 FixedColor = clBtnFace FixedHotColor = cl3DLight Options = [dgEditing, dgTitles, dgIndicator, dgColumnResize, dgColumnMove, dgColLines, dgRowLines, dgTabs, dgAlwaysShowSelection, dgConfirmDelete, dgCancelOnExit] OptionsExtra = [dgeAutoColumns, dgeCheckboxColumn] ParentColor = False TabOrder = 0 TabStop = True end object DBNavigator1: TDBNavigator Left = 152 Height = 25 Top = 248 Width = 241 BevelOuter = bvNone ClientHeight = 25 ClientWidth = 241 DataSource = Datasource1 end object MySQL50Connection1: TMySQL50Connection Connected = True Streamedconnected = True DatabaseName = 'test' Password = 'test' Transaction = SQLTransaction1 UserName = 'root' left = 24 top = 9 end object SQLQuery1: TSQLQuery Active = True Database = MySQL50Connection1 Transaction = SQLTransaction1 SQL.Strings = ( 'select * from zipcode' 'order by zip' ) Params = <> UpdateMode = upWhereChanged UsePrimaryKeyAsKey = True // YES! UsePrimaryKeyAsKey is set to True! ParseSQL = True left = 24 top = 44 end object SQLTransaction1: TSQLTransaction Database = MySQL50Connection1 left = 59 top = 9 end object Datasource1: TDatasource DataSet = SQLQuery1 left = 59 top = 44 end end I did not add any code at all to the main PAS file, so the project and source are as follows: program zipcode; {$mode objfpc}{$H+} uses {$IFDEF UNIX}{$IFDEF UseCThreads} cthreads, {$ENDIF}{$ENDIF} Interfaces, // this includes the LCL widgetset Forms { you can add units after this }, zipcode, SQLDBLaz; begin Application.Initialize; Application.CreateForm(TForm1, Form1); Application.Run; end. +++++ unit Zipcode; {$mode objfpc}{$H+} interface uses Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs, mysql50conn, sqldb, db, DBGrids, DbCtrls; type { TForm1 } TForm1 = class(TForm) Datasource1: TDatasource; DBGrid1: TDBGrid; DBNavigator1: TDBNavigator; MySQL50Connection1: TMySQL50Connection; SQLQuery1: TSQLQuery; SQLTransaction1: TSQLTransaction; private { private declarations } public { public declarations } end; var Form1: TForm1; implementation initialization {$I zipcode.lrs} end. BTW, I did get rid of the exception on close by adding an event handler for formclose that closes the database. And I was able to get an insert to work by adding an event handler to the navigator component that did SQLQuery1.Appyupdates in response to nbPost button click. However, delete and edit still do not work. -- Howard Lee Harkness www.celtic-fiddler.com
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