I have Dragged&Dropped a datasource to a WinForm and got myself a good user interface with the datagridview and the navigator, but ...

When the user DELETEs a row of data in the datagridview and confirms this deleting, the row disappears from the datagridview and I update the database.

BUT maybe the row should NOT be deleted because violation of "Foreign key constraint" - I inform the user of this error but how can I get the "deleted" row back in the datagridview again - it's not a good practice to just FILL in data again because the user COULD have changed some other data in the datagridview and these changes will the be lost !

What are "the best practice" for this deleting ?

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Best regards KSO, Denmark

Ok
U vcan make sure when deleting, just as the user confirms that he wnts to delete the row ,take that rows data,
and chk in database whether it is being used in some other table(as foreign key) if so then dont perform delete operation , put a msg to user saying cannot be deleted as this particular row data is being used in table(ur table name) . Then the row cannot be removed .

If it is not being used else where then just delete it.

I hope u got what i m trying to say.If u dont,DO let me knw.

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Meghana Lohit

HI PSAKSor
Based on what i read , i think u want to inform the user that this particular row cannot be deleted due to so n so reasons, and not delete the row???
Correct me if i m wrong

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Meghana Lohit

Yeah - that's right BUT ...

please remark that I'm using this Drag&Drop-method and then I have not so much code to fool around in !

"By design" I update after every attemp to delete.

These "so n so reasons" in this particular case is "a violation of a foreign key constraint" and this is found out AFTER the row is deleted in the datagridview on the form !

I would like to "find out this FKC-error BEFORE the row is removed from the datagridview.

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Best regards KSO, Denmark

Ok
U vcan make sure when deleting, just as the user confirms that he wnts to delete the row ,take that rows data,
and chk in database whether it is being used in some other table(as foreign key) if so then dont perform delete operation , put a msg to user saying cannot be deleted as this particular row data is being used in table(ur table name) . Then the row cannot be removed .

If it is not being used else where then just delete it.

I hope u got what i m trying to say.If u dont,DO let me knw.

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Meghana Lohit

Yeah, yeah you'r so right BUT ...

you don't see: "... that I'm using this Drag&Drop-method and then I have not so much code to fool around in !"

The user maybemake some editation and then deletes a row (I update the db after every deleting !)

- they only thing I can do after the users deletes a rowis start theupdate and THEN "the train is running" and the FKC-error comes up.

I think there MUST be an event like "TryDeleteAndSeeWhatErrorComesUp_IfAny" and the I can manage from here.

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Best regards KSO, Denmark

Ya no problem if u r using that. I think u must be using a delete button when user deletes a row so u can put this
take that rows data,
and chk in database whether it is being used in some other table(as foreign key) if so then dont perform delete operation , put a msg to user saying cannot be deleted as this particular row data is being used in table(ur table name) . Then the row cannot be removed .

u need not put this in drag and drop method,correct me if i m wrong
Can u tel if u using windows form or User control

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Meghana Lohit

I use Windows forms.

This Drag&Drop-method for getting a well functioning user interface is fantastic I think BUT ...

I can't imaging that it's created WITHOUT thinking of this kind of error in mind - so I'm sure there must be an "beforedeleteEvent" I can use ... but I can't find our how.

OK you can code, code and code your own solution from scratch, but I try to minimize the amount of code ... but sometimes run into troubles - this is one of them !

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Best regards KSO, Denmark

Ok well i don knw abt this. I thought u r using usual windows form.I ve no clue abt this .
just try this i m not sure if it ll help
http://msdn.microsoft.com/en-us/library/aa157412(office.10).aspx
http://msdn.microsoft.com/en-us/library/aa209979(office.11).aspx
http://msdn.microsoft.com/en-us/library/yt37dwbw(VS.80).aspx
http://msdn.microsoft.com/en-us/library/aa227135(VS.60).aspx

http://help.lockergnome.com/office/AppointmentItem-BeforeDelete-Event--ftopict978811.html

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Meghana Lohit