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Compare Two Identical Datatable By Content

I have 2 datatables. They are identical. I want to compare them by
cell's content. They are all same.

But dt1 == dt2 or
dt1.GetHashCode () == dt2.GetHashCode () doesn 't work.

There are big amount of rows in theese datatables . So i don 't want
to enumerate each rows. This is not efficient and unacceptable for my
current application.

So how can i compare theese datatables by their contents?

Let me describe more in detail :

I have a datatable. dtOld.
In the form load event i am filling this datatable from database and
bound it to a grid.

User may change some data in the grid. Then press save button. At this
point, i can sense which row changed (.GetChanges) and update this row
to database.

So - here is my problem begins :

After this update operation i am requerying the new table from
database and name is as dtNew datatable.

And i already have a datatable which is bound to grid. called dtOld.
I am accepting changes on dtOld.

If no other user made any changes , dtOld and dtNew are same.

In debug mode i can see that they have exact same data.
for instance both of them have 10 rows. and same data in columns.

But when i compared them c# says they are not equal. In theory they
might not equal by reference . Right. But i want to compare by their
content.

How can i manage this in efficient way ?

Regards.
Dec 18 '06
11 35432
(ignore; wrong topic)
Dec 19 '06 #11
On Tue, 19 Dec 2006 10:33:56 -0000, "Marc Gravell"
<ma**********@g mail.comwrote:
>Why do it this way? Personally, I'd just look for the records that the
user has actively changed, and attempt to save them to the database,
letting the database tell me about concurrency issues (for instance,
by verifying a "timestamp" column at hte point of save). Otherwise, to
ensure that no users change things behind your back you would have to
lock all of the data while checking, which doesn't seem very
efficient. Of course, locking the rows in question is a good idea
(TransactionSc ope or ADO.Net transaction).
Assume that i have 5 rows when i 've load form.
1
2
3
4
5

user changed number 4. and i 've updated this info to database. by the
way - user 2 deleted the record number 2 and user three updated the
number four.

I want current user to see fresh data. that 's why i 'm checking.
>Also, by the time you have
fetched all the data from the database, updating the UI is the least
of your issues, so if you have the data, just update it. But if the
data is large, you shouldn't really attempt to do it this way
anyway...
data is too large.
>There are also (in 2.0) database-oriented change notifications (works
best with SqlServer 2005), but I'm not a big fan of these... not sure
about the scalability... maybe I'm prejudiced though...

Marc
my application using both MSSQL2005 and Oracle and other databases
that supports stored procedure.
Dec 19 '06 #12

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