如何在数据表中获取FirstOrDefault添加/更新/删除的数据行？

Question

I'm developing an external .dll that my Epicor ERP calls in a BPM's pre/post processing. The .dll is written in C# and Epicor passes the .dll a dataset.

I've seen code examples that either get changed rows or FirstOrDefault but not both.

This code is always null so my do something never gets called.

var ttQuoteDtl = ds.QuoteDtl.Where(r => r.RowMod == IceRow.ROWSTATE_ADDED || r.RowMod == IceRow.ROWSTATE_UPDATED || r.RowMod == IceRow.ROWSTATE_DELETED);

var ttQuoteDtl_xRow = (from ttQuoteDtl_Row in ttQuoteDtl select ttQuoteDtl_Row).FirstOrDefault(); 

if (ttQuoteDtl_xRow != null)
{
  //Do Something 
}

I can get ttQuoteDtl to not be null and perform some work if I call it like this:

var ttQuoteDtl_xRow = ds.QuoteDtl.FirstOrDefault();

But I'm concerned it won't be a row that has been added, updated or deleted.

Answer 1

You can just combine the two, Linq statements are composable.

var quoteDtlRow = 
    ds.QuoteDtl
    .Where(r => 
        r.RowMod == IceRow.ROWSTATE_ADDED || 
        r.RowMod == IceRow.ROWSTATE_UPDATED || 
        r.RowMod == IceRow.ROWSTATE_DELETED
    ).FirstOrDefault();

If this is always null then we may need to see some more code.

Incidentally, if DS is the dataset passed into the BPM method then a row from ds.QuoteDetail implements the IceRow interface. This provides the methods .Added() , .Updated() , .Deleted() and .Unchanged() meaning the above can be shortened to

var quoteDtlRow = 
    ds.QuoteDtl
    .Where(
        r => !r.Unchanged()
    ).FirstOrDefault();