How to create a two phase commit with Delphi and InterBase

This week i was given a 2h webinar over Understanding Transactions with InterBase and Delphi ( a playback you can find here LINK ).

One open Question was how to create a two phase commit with IBX in Delphi.

Follow these steps and you have created your first two phase commit application:

1. Create a new Delphi Project
2. Place for (minimum) 2 InterBases Databases a TIBDataBase Component
3. Edit the connection String from the TIBDataBase Components to connect diffrent databases
   - for example
   - database1 ->127.0.0.1:c:\data\employee_1.ib
   - database2 ->127.0.0.1:c:\data\employee_2.ib
4. Place 5 Buttons with following Captions
   - add database
   - start transaction
   - run queries
   - commit transaction
   - rollback tranaction
5. Add ONE TIBTransaction component
6. Place two TIBQuery Components (you can use later also TIBDataSet for showing data in a gird or what ever)
7. edit the SQL Property of each TIBQueryComponent
   - update table1 set Field1=’Ernie’ where ID=1
   - update table2 set Field1=’Bert’ where ID2
   table1 is in this example a table in DataBase1 and
   table2 is in this example a table in DataBase2
8. set of IBQuery1 properties:
   - DataBase -> IBDataBase1
   - Transaction -> IBTransaction1
9. set of IBQuery2 properties:
   - DataBase -> IBDataBase2
   - Transaction -> IBTransaction1
10. insert this code in the button with the caption “Add DataBase”
     IBTransaction1.AddDatabase(IBDatabase1);
     IBTransaction1.AddDatabase(IBDatabase2);
11. insert this code in the button with the caption “start transaction”
     IBTransaction1.StartTransaction;
12. insert this code in the button with the caption “run queries”
    IBQuery1.ExecSQL;
    IBQuery2.ExecSQL;
13. insert this code in the button with the caption “commit transaction”
    IBTransaction1.Commit;
14. insert this code in the button with the caption “rollback transaction”
    IBTransaction1.Rollback;
15. in the form event on create open both databases and also on close do not forget to close the databses
16. Compile
17. Run and have fun

end;

 

that’s all folks

 

regards daniel