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c#asp.net-mvclinqlinq-to-sql
Kathiravan
Kathiravan

Reputation: 55

C# Linq to SQL:cannot add an entity that already exists

I am using Linq for Insert,Delete and update the database in my code. While inserting data using InsertOnSubmit, I Am getting the cannot add an entity that already exists Exception. Please have a look my code

private static void AddNewPriceSettings(PRICE_SETTING priceSettingsInfo)
{
   PRICE_SETTING priceSetting = new PRICE_SETTING();
   priceSetting = priceSettingsInfo;           
   DataContext.CommonUsers.PRICE_SETTINGs.InsertOnSubmit(priceSettingsInfo);          
   DataContext.CommonUsers.SubmitChanges();
}

Upvotes: 2

Views: 6191

Answers (3)

user900202
user900202

Reputation:

just set the properties for the new priceSetting.

private static void AddNewPriceSettings(PRICE_SETTING priceSettingsInfo)
{
   PRICE_SETTING priceSetting = new PRICE_SETTING();
   //
   priceSetting.Prop1 = priceSettingsInfo.Prop1;
   priceSetting.Prop2 = priceSettingsInfo.Prop2;
   priceSetting.Prop3 = priceSettingsInfo.Prop3;
   // ...
   DataContext.CommonUsers.PRICE_SETTINGs.InsertOnSubmit(priceSetting );          
   DataContext.CommonUsers.SubmitChanges();
}

Upvotes: 2

Anders Arpi
Anders Arpi

Reputation: 8417

cannot add an entity that already exists

The problem is clearly stated by the error message. You already have a row in your database that contains the same entity as the one you are trying to insert.

How does SQL decide if two items are "the same"? It uses a key column, which usually is an integer id.

So that leads me to ask you - how does your column definitions look for the affected table? And where are you getting the PRICE_SETTING that is passed into the method?

The problem could also be that you are trying to perform an update on an already existing object - in that case you need to use different methods. Please share more info regarding the context.

Upvotes: 0

CodeCaster
CodeCaster

Reputation: 151738

If you call AddNewPriceSettings() using an existing PRICE_SETTING object, you're indeed trying to add it again. The second line in your method does that. The new PRICE_SETTING(); you create on the first line is then not referenced to anymore and will be GC'ed without trying to insert it.

If you want to create a copy, you'll have to clone the priceSettingsInfo into the priceSetting variable (you can use various techniques for that) prior to inserting and submitting it.

Upvotes: 0

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