Databases
StackOverflow2013
Postsdbo
POC# error in Parallel.ForEach
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POC# error in Parallel.ForEach
    primarykey
    data
    text
    <p>I have a strange problem that I am unable to debug. Here's a delegate that parses information:</p> <pre><code>Action&lt;XElement, String&gt; ParseXMLInfo = (s, t) =&gt; { using (var Ctx = new Entities ()) { var Records = s.Elements ("record"); Parallel.ForEach ( ParallelEnumerable.Range (0, Records.Count ()), u =&gt; { var el = Records.ElementAt (u); try { var NTR = new tbl_UserInfo (); NTR.first_name = el.Element ("first_name").Value; NTR.last_name = el.Element ("last_name").Value; Ctx.AddTotbl_UserInfo (NTR); } catch (Exception excp) { Console.WriteLine (System.DateTime.Now + " " + excp.Message); } } ); Ctx.SaveChanges (); } }; </code></pre> <p>The delegate itself is called twice, as follows:</p> <pre><code>Parallel.Invoke ( () =&gt; { var XMLDoc_MaleInfo = XElement.Load ("MaleNames.xml"); Console.WriteLine ("Fetching records from MaleNames.xml; starting at " + System.DateTime.Now); ParseXMLInfo (XMLDoc_MaleInfo, "male"); }, () =&gt; { var XMLDoc_FemaleInfo = XElement.Load ("FemaleNames.xml"); Console.WriteLine ("Fetching records from FemaleNames.xml; starting at " + System.DateTime.Now); ParseXMLInfo (XMLDoc_MaleInfo, "female"); } ); </code></pre> <p>Everything appears to run correctly. In particular, the Parallel.ForEach portion of the delegate runs without any error. But then the code breaks at the line Ctx.SaveChanges (), with the message "Object reference not set to an instance of an object." But when I hover over Ctx (in this broken state), Ctx is not shown to be null.</p> <p>Can someone please tell me what is going on? Thanks in advance.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USShredderroy
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COCan you post your `Entities` class? I suspect it's not threadsafe. And you're writing to it from multiple threads.
      singulars
      1. POC# error in Parallel.ForEach
      1. USCodesInChaos
    2. CO@CodeInChaos The Entities class was generated by .NET when I added an ADO.NET Entity Data Model. I did not modify the code that was generated for it by the system itself. If you really want, I can post the entire file, but it is quite long.
      singulars
      1. POC# error in Parallel.ForEach
      1. USShredderroy
    3. CO@CodeInChaos You are probably on to something. When I comment out the "try" and "catch" lines, I get the following error for AttTotbl_UserInfo: "The type Test.tbl_UserInfo has been mapped more than once."
      singulars
      1. POC# error in Parallel.ForEach
      1. USShredderroy
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload