[C#] linq exception handling in a query?

1,022 · July 22, 2011

If you get an exception while trying to make a nested query a dictionary that states a same key has already been added is there a way of actually seeing the key that is attempted to be added? In the debugger it just says the error of an key already exists with a stack trace of (I took out the actual path names):

   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector)
   at a.MainWindow.&lt;&gt;c__DisplayClass4a.&lt;refreshClientLocks&gt;b__14(DataRow acc_dr) in a\MainWindow.xaml.cs:line 301
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector)
   at a.MainWindow.&lt;refreshClientLocks&gt;b__12(&lt;&gt;f__AnonymousType0`2 &lt;&gt;h__TransparentIdentifier5) in a\MainWindow.xaml.cs:line 299
   at System.Linq.Enumerable.&lt;&gt;c__DisplayClass12`3.&lt;CombineSelectors&gt;b__11(TSource x)
   at System.Linq.Enumerable.&lt;&gt;c__DisplayClass12`3.&lt;CombineSelectors&gt;b__11(TSource x)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.SystemCore_EnumerableDebugView`1.get_Items()

1,784 · July 22, 2011

Have you tried inspecting the Exception's .Message? Then its InnerException's Message. Then the InnerException's InnerException? (ad infinitum, you get the idea..)

They may give you some clue.

1,022 · July 22, 2011

yes, the inner exception is null, which makes sense b/c it's throwing the exception since a key is being added to a dictionary that already has that key definition. Since it is in a query I can't see which (to my knowledge at least)

key is attempting to be added twice.

1,784 · July 22, 2011

Without actually knowing anything about the code itself, I'm stabbing in the dark here. Is it possible to do debug prints, and see the last one it prints before the exception happens?

8,753 · July 23, 2011

I think you need to break down your query into smaller subqueries so you're able to inspect their values individually.

1,022 · July 23, 2011

Not sure how to break this into smaller queries without compromising performance at a terrible rate:

var clientQuery = from DataRow client_dr in this.gl_aeiMgr.ClientsDataSet.Tables[this.gl_aeiMgr.ClientsTbl].Rows
                                                  let clientId = client_dr.Field&lt;string&gt;("userAccessId")
                                                  let accList = (from DataRow acc_dr in this.gl_aeiMgr.ClientsAccDataSet.Tables[this.gl_aeiMgr.ClientsAccTbl].Rows
                                                                 where acc_dr.Field&lt;string&gt;("clientID") == clientId
                                                                 select new
                                                                 {
                                                                     AccId = acc_dr.Field&lt;string&gt;("userAccessId"),
                                                                     AccDefObj = new AccDef(acc_dr.Field&lt;string&gt;("userAccessId"), clientId, acc_dr.Field&lt;int&gt;("acc_num"), (AccType)Enum.Parse(typeof(AccType), acc_dr.Field&lt;string&gt;("acc_type")),
                                                                         (AccBillCycle)Enum.Parse(typeof(AccBillCycle), acc_dr.Field&lt;string&gt;("accScheduleType")),
                                                                         (from DataRow benf_dr in this.gl_aeiMgr.ClientsBenfDataDet.Tables[this.gl_aeiMgr.ClientsBenfTbl].Rows
                                                                          let benfAccId = benf_dr.Field&lt;string&gt;("userAccessId")
                                                                          where benf_dr.Field&lt;string&gt;("benfAccId") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                          select new BenfDef(benf_dr.Field&lt;string&gt;("userAccessId"), benfAccId, benf_dr.Field&lt;string&gt;("benfFirstName"), benf_dr.Field&lt;string&gt;("benfLastName"), benf_dr.Field&lt;string&gt;("benfMiddleInit"),
                                                                              benf_dr.Field&lt;string&gt;("benfSSN"), benf_dr.Field&lt;DateTime&gt;("benfDOB"), benf_dr.Field&lt;double&gt;("benfPercent"), benf_dr.Field&lt;string&gt;("benfAddrStreet"),
                                                                              benf_dr.Field&lt;string&gt;("benfAddrCity"), (Globals.USPSStateCodes)Enum.Parse(typeof(Globals.USPSStateCodes), benf_dr.Field&lt;string&gt;("benfAddrState")),
                                                                              benf_dr.Field&lt;string&gt;("benfAddrZipCode"), benf_dr.Field&lt;string&gt;("benfAddrCountry"), benf_dr.Field&lt;string&gt;("benfPPhone"), (PhoneContactType)Enum.Parse(typeof(PhoneContactType), benf_dr.Field&lt;string&gt;("benfPPhoneType")))).ToDictionary(o =&gt; o.BenfId, o =&gt; o),
                                                                         (from DataRow benf_dr in this.gl_aeiMgr.ClientsSBenfDataSet.Tables[this.gl_aeiMgr.ClientsSBenfTbl].Rows
                                                                          let benfAccId = benf_dr.Field&lt;string&gt;("userAccessId")
                                                                          where benf_dr.Field&lt;string&gt;("benfAccId") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                          select new BenfDef(benf_dr.Field&lt;string&gt;("userAccessId"), benfAccId, benf_dr.Field&lt;string&gt;("benfFirstName"), benf_dr.Field&lt;string&gt;("benfLastName"), benf_dr.Field&lt;string&gt;("benfMiddleInit"),
                                                                              benf_dr.Field&lt;string&gt;("benfSSN"), benf_dr.Field&lt;DateTime&gt;("benfDOB"), benf_dr.Field&lt;double&gt;("benfPercent"), benf_dr.Field&lt;string&gt;("benfAddrStreet"),
                                                                              benf_dr.Field&lt;string&gt;("benfAddrCity"), (Globals.USPSStateCodes)Enum.Parse(typeof(Globals.USPSStateCodes), benf_dr.Field&lt;string&gt;("benfAddrState")),
                                                                              benf_dr.Field&lt;string&gt;("benfAddrZipCode"), benf_dr.Field&lt;string&gt;("benfAddrCountry"), benf_dr.Field&lt;string&gt;("benfPPhone"), (PhoneContactType)Enum.Parse(typeof(PhoneContactType), benf_dr.Field&lt;string&gt;("benfPPhoneType")))).ToDictionary(o =&gt; o.BenfId, o =&gt; o),
                                                                         HelperUtils.ToObservableCollection&lt;PmtDef&gt;((from DataRow pmt_dr in this.gl_aeiMgr.ClientsPmtDSet.Tables[this.gl_aeiMgr.ClientsPmtTbl].Rows
                                                                                                                     where pmt_dr.Field&lt;string&gt;("accId") == acc_dr.Field&lt;string&gt;("userAccessId") &amp;&amp; pmt_dr.Field&lt;bool&gt;("pmtIsExp") == false
                                                                                                                     select new PmtDef(pmt_dr.Field&lt;string&gt;("userAccessId"), pmt_dr.Field&lt;DateTime&gt;("pmtEffDate"), pmt_dr.Field&lt;double&gt;("pmtAmt"),
                                                                                                                     false, pmt_dr.Field&lt;bool&gt;("pmtIsStmt"), pmt_dr.Field&lt;DateTime&gt;("pmtExpDate"), pmt_dr.Field&lt;string&gt;("pmtChkNum"))).AsEnumerable&lt;PmtDef&gt;()), null, null, null,
                                                                                                                     (from DataRow certList_dr in this.gl_aeiMgr.ClientsCertListDSet.Tables[this.gl_aeiMgr.ClientsCertLstTbl].Rows
                                                                                                                      where certList_dr.Field&lt;string&gt;("accID") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                                                                      select new CertDef(certList_dr.Field&lt;string&gt;("userAccessId"), certList_dr.Field&lt;int&gt;("certNum"), certList_dr.Field&lt;double&gt;("certAmt"))).GroupBy(o =&gt; o.CertAmt).ToDictionary(o =&gt; o.Key, o =&gt; o.ToList&lt;CertDef&gt;()),
                                                                                                                          (from DataRow note_dr in this.gl_aeiMgr.ClientsNotesDSet.Tables[this.gl_aeiMgr.ClientsNotesTbl].Rows
                                                                                                                           where note_dr.Field&lt;string&gt;("accId") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                                                                           select new NoteDef(note_dr.Field&lt;string&gt;("noteNum"), note_dr.Field&lt;string&gt;("noteNum"), note_dr.Field&lt;DateTime&gt;("noteDateEff"),
                                                                                                                               note_dr.Field&lt;DateTime&gt;("noteDateExp"), (AccBillCycle)Enum.Parse(typeof(AccBillCycle), note_dr.Field&lt;string&gt;("noteBillCycle"), true), note_dr.Field&lt;bool&gt;("noteIsPaid"), note_dr.Field&lt;double&gt;("notePmt"))).ToDictionary(o =&gt; o.NoteId, o =&gt; o),
                                                                                                                                   (from DataRow rel_dr in this.gl_aeiMgr.ClientsRelConDSet.Tables[this.gl_aeiMgr.ClientsRelConTbl].Rows
                                                                                                                                    where rel_dr.Field&lt;string&gt;("accId") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                                                                                    select new RelContactDef(rel_dr.Field&lt;string&gt;("userAccessId"), rel_dr.Field&lt;string&gt;("fName"), rel_dr.Field&lt;string&gt;("lName"), rel_dr.Field&lt;string&gt;("addrStreet"), rel_dr.Field&lt;string&gt;("addrCity"),
                                                                                                                                        (Globals.USPSStateCodes)Enum.Parse(typeof(Globals.USPSStateCodes), rel_dr.Field&lt;string&gt;("addrState"), true), rel_dr.Field&lt;string&gt;("addrZipCode"),
                                                                                                                                        rel_dr.Field&lt;string&gt;("addrCountry"), rel_dr.Field&lt;string&gt;("phone"), rel_dr.Field&lt;string&gt;("company"), rel_dr.Field&lt;string&gt;("email"))).ToDictionary(o =&gt; o.RelContactId, o =&gt; o),
                                                                                                                                            (from DataRow frm_dr in this.gl_aeiMgr.ClientsAccFormsDset.Tables[this.gl_aeiMgr.ClientsAccFormsTbl].Rows
                                                                                                                                             where frm_dr.Field&lt;string&gt;("clientsAccID") == acc_dr.Field&lt;string&gt;("userAccessId")
                                                                                                                                             select new FrmDetailLstDef(frm_dr.Field&lt;string&gt;("userAccessId"), frm_dr.Field&lt;string&gt;("formName"), (FrmStatus)Enum.Parse(typeof(FrmStatus), frm_dr.Field&lt;string&gt;("formStatus"), true), frm_dr.Field&lt;DateTime&gt;("formDateCreated"), frm_dr.Field&lt;string&gt;("formLocation"))).ToDictionary(o =&gt; o.FrmId, o =&gt; o))
                                                                 }).ToDictionary(o =&gt; o.AccId, o =&gt; o.AccDefObj)
                                                  select new ClientDef(clientId, client_dr.Field&lt;string&gt;("fName"), client_dr.Field&lt;string&gt;("middleInit"), client_dr.Field&lt;string&gt;("lName"),
                                                      client_dr.Field&lt;string&gt;("ssn"), client_dr.Field&lt;string&gt;("pPhone1Num"), (client_dr.Field&lt;string&gt;("pPhone1Ext") != null) ? client_dr.Field&lt;string&gt;("pPhone1Ext") : "", (client_dr.Field&lt;string&gt;("pPhone2Num") != null) ? client_dr.Field&lt;string&gt;("pPhone2Num") : "",
                                                      (client_dr.Field&lt;string&gt;("pPhone2Ext") != null) ? client_dr.Field&lt;string&gt;("pPhone2Ext") : "", ClientMgr.ConvertPhoneTypeFromStr(client_dr.Field&lt;string&gt;("pPhone1Type")),
                                                      ClientMgr.ConvertPhoneTypeFromStr(client_dr.Field&lt;string&gt;("pPhone2Type")), client_dr.Field&lt;string&gt;("mAddrStreet"), ClientMgr.ConvertStateCodeFromStr(client_dr.Field&lt;string&gt;("mAddrState")),
                                                      client_dr.Field&lt;string&gt;("mAddrZipCode"), client_dr.Field&lt;string&gt;("mAddrCity"), client_dr.Field&lt;string&gt;("mAddrCountry"), accList, client_dr.Field&lt;string&gt;("mFaxContact"), client_dr.Field&lt;string&gt;("pEmailAddr"), client_dr.Field&lt;DateTime&gt;("clientDOB"),
                                                      client_dr.Field&lt;int&gt;("ppmNum"), client_dr.Field&lt;double&gt;("ppmInvestNum"));

2,659 · July 23, 2011

Do it with a smaller dataset only for debugging. Doc's suggestion is money.

1,022 · July 23, 2011

ah, ok, I'll play around with it. Thanks guys I'll post my results :)

8,753 · July 23, 2011

On 23/07/2011 at 01:38, sathenzar said:
Not sure how to break this into smaller queries without compromising performance at a terrible rate

It might, but that's just for debugging. You can restore the original query once you find the bug.

1,022 · July 23, 2011

the bug was not within the query, it was another piece of code that was pointing to the wrong table. I didn't catch it b/c the only difference between the two datasets/table names is one has an S in the middle of it and one does not. So it was grabbing the information out of the wrong table. Thanks for the help guys!

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[C#] linq exception handling in a query?

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