Update records using SqlDataAdapter

[Matteo Migliore]

Hi.

I writed a method that takes two DataTable with same schema
and return a third DataTable that:
- insert new rows from "compare" DataTable
- delete rows contained in "source" and not in "compare" DataTable
- update rows from "compare"

--------------------------------------
public static DataTable GetMergedTable(DataTable source, DataTable compare)
{
DataTable ret = new DataTable();
ret.Merge(source);
ret.Merge(compare);
ret.AcceptChanges();

for (int i = 0; i < ret.Rows.Count; i++) {
DataRow row = ret.Rows;

bool sourceFound = source.Rows.Find(row["id"]) != null;
bool compareFound = compare.Rows.Find(row["id"]) != null;

//Row added
if ((!sourceFound) && (compareFound))
row.SetAdded();

//Row modified
if ((sourceFound) && (compareFound))
row.SetModified();

//Row deleted
if ((sourceFound) && (!compareFound))
row.Delete();
}

return ret;
}
--------------------------------------

When I execute an update with SqlDataAdapter.Update
rows are inserted and deleted correctly, but never updated.

What is the problem?

Thx! ;-)
Matteo Migliore.

 

[Cor Ligthert[MVP]]

Matteo,

Acceptchanges says that you have updated them and the changes can be set as
done in the datatables.

Cor

 

[Matteo Migliore]

Acceptchanges says that you have updated them and the changes can be

set as done in the datatables.

The problem is not in AcceptChanges because this method
only change the row state to Unchanged, but with the "for"
I set rows in correct status.

Read here:
http://www.devnewsgroups.net/group/microsoft.public.dotnet.framework.adonet/topic16270.aspx

Thx! ;-)
Matteo Migliore.

 

[Cor Ligthert [MVP]]

I don't see in the message thread that it is solved.

By the way, this is just a copy of a Microsoft AdoNet newsgroup discussion.

http://groups.google.nl/group/micro...7b385ef555a/39a346c8aad9c860#39a346c8aad9c860

In my idea you should be able to do the GetChanges direct, which gives you
only a shallow copy and be able because of that to do the updates. A
acceptchanges does set all to unchanged, however after that it has updated
the changes on the old data, in fact it is SetChanges and AcceptChanges in
one. . For new and delete this is of course not the question.

Cor

 

[Matteo Migliore]

In my idea you should be able to do the GetChanges direct, which

gives you only a shallow copy and be able because of that to do the
updates. A acceptchanges does set all to unchanged, however after
that it has updated the changes on the old data, in fact it is
SetChanges and AcceptChanges in one. . For new and delete this is of
course not the question.

Thank you, but I don't understand how to solve this problem .

I need to compare two DataTable, the first contains the old data
and the second contains the new data. How can I do?

Merge and GetChanges doesn't go beacuse the second DataTable
is readed from a XML file. So does not contain activity
on rows, they are all on Unchanged status, initially.

Thx! ;-)
Matteo Migliore.