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POCollection property not properly added to parent on save
 

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  1. POCollection property not properly added to parent on save
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    <p>Look at the following code example. </p> <p>What it does:</p> <ol> <li>Iterates a bunch of customers. If it already knows the customer, it retrieves the existing database object for that customer (this is the problem-ridden part). Otherwise, it creates a new object (this works fine).</li> <li>All loans where the social security number matches (CPR) will be added to the new or existing customer.</li> </ol> <p>The problem: it works for new customer objects, but when I retrieve an existing customer object, the loans lose their relation to the customer when saved (CustomerID = null). They are still saved to the database.</p> <p>Any ideas?</p> <pre><code>protected void BuildCustomerData() { Console.WriteLine(" Starting the customer build."); var counter = 0; var recycleCount = 100; var reportingCount = 100; var sTime = DateTime.Now; var q = from c in db.IntermediaryRkos select c.CPR; var distincts = q.Distinct().ToArray(); var numbersToProcess = distincts.Count(); Console.WriteLine(" Identified " + numbersToProcess + " customers. " + (DateTime.Now - sTime).TotalSeconds); foreach (var item in distincts) { var loans = from c in db.IntermediaryRkos where c.CPR == item select c; var existing = db.Customers.Where(x =&gt; x.CPR == item).FirstOrDefault(); if (existing != null) { this.GenerateLoanListFor(existing, loans); db.Entry(existing).State = System.Data.EntityState.Modified; } else { var customer = new Customer { CPR = item, }; this.GenerateLoanListFor(customer, loans); db.Customers.Add(customer); db.Entry(customer).State = System.Data.EntityState.Added; } counter++; if (counter % recycleCount == 0) { this.SaveAndRecycleContext(); } if (counter % reportingCount == 0) { Console.WriteLine(" Processed " + counter + " customers of " + numbersToProcess + "."); } } db.SaveChanges(); } protected void GenerateLoanListFor(Customer customer, IQueryable&lt;IntermediaryRko&gt; loans) { customer.Loans = new List&lt;Loan&gt;(); foreach (var item in loans.Where(x =&gt; x.DebtPrefix == "SomeCategory").ToList()) { var transformed = StudentLoanMap.CreateFrom(item); customer.Loans.Add(transformed); db.Entry(transformed).State = System.Data.EntityState.Added; } } </code></pre> <p><strong>EDIT 1:</strong></p> <p>As pointed out, I am manually setting the state. This is due to the RecycleContext call, which is implemented for maximum db transaction performance:</p> <pre><code>protected void SaveAndRecycleContext() { db.SaveChanges(); db.Dispose(); db = new SolutionDatabase(); db.Configuration.AutoDetectChangesEnabled = false; db.Configuration.ValidateOnSaveEnabled = false; } </code></pre>
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    1. PTQuestion
    1. USHarold Smith
    1. USHarold Smith
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    1. COI'd think the db recycling issue might be better managed by a using clause and scope management
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      1. USMaslow
    2. COGood tip, but it does not solve the current problem.
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      1. USHarold Smith
    3. CORe-enabling AutoDetectChangesEnabled and ValidateOnSaveEnabled does solve the original problem, but introduces a very large performance hit which I cannot accept. It is already a pretty operation that requires about an hour. With those features enabled, that would be about 4-5 hours.
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      1. POCollection property not properly added to parent on save
      1. USHarold Smith
 

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