Update Multiple Rows in Entity Framework from a list of ids

I am trying to create a query for entity framework that will allow me to take a list of ids and update a field associated with them.

Example in SQL:

UPDATE Friends
SET msgSentBy = '1234'
WHERE id IN (1, 2, 3, 4)

How do I convert the above into entity framework?

Solution 1:

something like below

var idList=new int[]{1, 2, 3, 4};
using (var db=new SomeDatabaseContext())
{
    var friends= db.Friends.Where(f=>idList.Contains(f.ID)).ToList();
    friends.ForEach(a=>a.msgSentBy='1234');
    db.SaveChanges();
}

UPDATE:

you can update multiple fields as below

friends.ForEach(a =>
                      {
                         a.property1 = value1;
                         a.property2 = value2;
                      });

Solution 2:

var idList=new int[]{1, 2, 3, 4};
var friendsToUpdate = await Context.Friends.Where(f => 
    idList.Contains(f.Id).ToListAsync();

foreach(var item in previousEReceipts)
{
  item.msgSentBy = "1234";
}

You can use foreach to update each element that meets your condition.

Here is an example in a more generic way:

var itemsToUpdate = await Context.friends.Where(f => f.Id == <someCondition>).ToListAsync();

foreach(var item in itemsToUpdate)
{
   item.property = updatedValue;
}
Context.SaveChanges()

In general you will most probably use async methods with await for db queries.

Solution 3:

I have created a library to batch delete or update records with a round trip on EF Core 5.

Sample code as follows:

await ctx.DeleteRangeAsync(b => b.Price > n || b.AuthorName == "zack yang");

await ctx.BatchUpdate()
.Set(b => b.Price, b => b.Price + 3)
.Set(b=>b.AuthorName,b=>b.Title.Substring(3,2)+b.AuthorName.ToUpper())
.Set(b => b.PubTime, b => DateTime.Now)
.Where(b => b.Id > n || b.AuthorName.StartsWith("Zack"))
.ExecuteAsync();

Github repository: https://github.com/yangzhongke/Zack.EFCore.Batch Report: https://www.reddit.com/r/dotnetcore/comments/k1esra/how_to_batch_delete_or_update_in_entity_framework/