Entity Framework Z Plus Batch Update

I am using Entity Framework Z Plus Batch Update method. I am unable to proceed due to below issue. Actually Update method works good when i give static values like tagName="amir1". But I need to get the Tagdescription from a web service or from another collection based on the tagId, Update method is not accepting a extension method or any other method to accomplish my requirement.Its saying

tagName="amir1"

Tagdescription

tagId

"LINQ to Entities does not recognize the method 'System.String GetTagDescription(Int32)' method, and this method cannot be translated into a store expression.".

Hope my requirement is clear now. Please guide me if there is any other approach for my requirement.

Here is my code:

using (var context = new TrialsDBEntities())

context.tblTags.Where(x => (tagIdCollection.Contains(x.tagId))).
Update(m => new tblTag tagDescription = m.tagId.GetTagDescription(), tagName = "amir1" );


public static string GetTagDescription(this int i)

return "test" + i;

///Replace above line with call to database or web service call
getting some text by giving i as input



2 Answers
2

Write your code as follows:

using (var context = new TrialsDBEntities())

var tagsToBeUpdated = context.tblTags.Where(x => (tagIdCollection.Contains(x.tagId))).AsNoTracking().ToList();

//Only use this code block if your tagsToBeUpdated list is too large
Parallel.ForEach(tagsToBeUpdated, tagToBeUpdated =>

var tagDescription = GetTagDescription(tagToBeUpdated.tagId);
tagToBeUpdated.tagDescription = tagDescription;
context.Entry(tagToBeUpdated).State = EntityState.Modified;
);

//Only use this code block if your tagsToBeUpdated list is not too large
foreach(var tagToBeUpdated in tagsToBeUpdated)

var tagDescription = GetTagDescription(tagToBeUpdated.tagId);
tagToBeUpdated.tagDescription = tagDescription;
context.Entry(tagToBeUpdated).State = EntityState.Modified;


context.SaveChanges();


public static string GetTagDescription(int i)

return "test" + i;

///Replace above line with call to database or web service call
//getting some text by giving i as input



Disclaimer: I'm the owner of the project Entity Framework Plus

Unfortunately, that's not possible to use BatchUpdate with a value that changes from a row to another.

Disclaimer: I'm the owner of the project Entity Framework Extensions

In this situation, we normally recommend using our paid library that's build for this kind of situation and offer high-performance saving operation.

Example

// Easiest way
context.BulkSaveChanges();

// Fastest way
context.BulkUpdate(tags);


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