DataViewRowState filter not working

  • Thread starter Thread starter CNHS
  • Start date Start date
C

CNHS

I am trying to compare the original value of a specified column to its new
modified value, using the DataViewRowState filter. However, both the
original value and the new value are returning the new value. Can anyone
figure out what I am doing wrong?

Here is the code:
rowsOriginal = DsVendors1.TBL_VENDORS.Select("", "",
DataViewRowState.ModifiedOriginal)
rowsCurrent = DsVendors1.TBL_VENDORS.Select("", "",
DataViewRowState.ModifiedCurrent)

daVendors.Update(DsVendors1, "AP_TBL_VENDORS")

I put in the last line of code to show you that I am not calling the Update
until after I set the rows. I know calling the Update would call
AcceptChanges and then I would not have any Modified rows at all. I am
changing a value in the TBL_Vendors, but when I check that value in
rowsOriginal and rowsCurrent, they both return the new value. I know I have
Modified rows because the rowsOriginal.Length and rowsCurrent.Length are
both =1.

Can anyone help?
 
I am not sure what it is you are trying to do, or even what your code is
doing.

There is only ever one set of rows. Your variables may have pointers to a
subset of those rows, but they are not copies of those rows. There is only
ever one set of them - and both the dataset and the variables you have point
to the same thing.

So, if a row because Unmodified in the dataset, it will in the variable you
are using to hold to on to a subset as well.

Maybe this isn't the issue, but I really couldn't follow what you were doing
here, or what you were checking after the Update and what kind of results
you were looking for.
 
Hi,

CNHS said:
I am trying to compare the original value of a specified column to its new
modified value, using the DataViewRowState filter. However, both the
original value and the new value are returning the new value. Can anyone
figure out what I am doing wrong?

Here is the code:
rowsOriginal = DsVendors1.TBL_VENDORS.Select("", "",
DataViewRowState.ModifiedOriginal)
rowsCurrent = DsVendors1.TBL_VENDORS.Select("", "",
DataViewRowState.ModifiedCurrent)

daVendors.Update(DsVendors1, "AP_TBL_VENDORS")

I put in the last line of code to show you that I am not calling the
Update until after I set the rows. I know calling the Update would call
AcceptChanges and then I would not have any Modified rows at all. I am
changing a value in the TBL_Vendors, but when I check that value in
rowsOriginal and rowsCurrent, they both return the new value. I know I
have Modified rows because the rowsOriginal.Length and rowsCurrent.Length
are both =1.

Can anyone help?
Click to expand...

DataTable.Select returns an array of DataRows. A modified DataRow always
contains both old and new values, you have to use the overloaded indexer to
get the old value:

oldValue = DsVendors1.TBL_VENDORS[rowIdx][colName, DataRowVersion.Original];

The DataViewRowState enum is also available on DataView.RowStateFilter where
it has more effect since the DataRowView's only expose one version of data.

HTH,
Greertings
 
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