 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
.NET Forum / Windows Forms / WinForm Data Binding / September 2006Problem when updating table with auto-id
Hello, I have table with auto-id. Binding to a datagridview. One interesting moment: - the first time I run the application, I type some rows(in datagridview), and press onto Update (call method update of the tableAdapter). I got the error message: record with the Id = 1 already existed. I have tested with some other tables and every time I got the same error. But if I add only one row at the first time, then from the second time when I open this form to add many new rows and after that I press onto button Update it works ok (without any error message). Pls explain. thanks.  SignatureContact: Bauman Moscow State Technical University Russia, Moscow 105005 Tel: +7915-426-6272 ICQ: 160-223-078 YM: Chipheo2k Hi, > Hello, > I have table with auto-id. Binding to a datagridview. One interesting [quoted text clipped - 6 lines] > to add many new rows and after that I press onto button Update it works ok > (without any error message). Pls explain. To support this auto-id in a batch mode, the DataColumn is set to AutoIncrement, then when the update is performed the DB generated keys are retrieved but *one* at a time. So, let's say you're adding three new records: id ... -- --- 0 ... 1 ... 2 ... The id's are generated by the DataColumn, now when you perform the update, the first row is inserted in the DB and it returns 1 as the key, but the second row currently also has 1 as the key, so it fails ... To avoid problems, set the DataColumn's AutoIncrementStep to -1, so the id's generated by the DataColumn are negative, while the ones generated by the DB are positive, this to avoid dupplicate keys *while* performing the update. To set the DataColumn's AutoIncrementStep, double click on your DataSet in solution explorer, select the id column inside the DataSet Schema Designer and then open properties window. HTH, Greetings > thanks. Such a greate idea, thanks a lot! SignatureContact: Bauman Moscow State Technical University Russia, Moscow 105005 Tel: +7915-426-6272 ICQ: 160-223-078 YM: Chipheo2k > Hi, > [quoted text clipped - 39 lines] > >> thanks. Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.