LINQ: How to remove element from IQueryable<T>
How do you loop through IQueryable and remove some elements I don't need.
I am looking for someth开发者_如何学Going like this
var items = MyDataContext.Items.Where(x => x.Container.ID == myContainerId);
foreach(Item item in items)
{
if(IsNotWhatINeed(item))
items.Remove(item);
}
Is it possible? Thanks in advance
You should be able to query that further as in this
var filtered = items.Where(itm => IsWhatINeed(itm));
Also notice the subtle change in the boolean function to an affirmative rather than a negative. That (the negative) is what the not
operator is for.
items = items.Where( x => !IsNotWhatINeed(x) );
var items = MyDataContext.Items.Where(x => x.Container.ID == myContainerId
&& !IsNotWhatINeed(x));
or
var items = MyDataContext.Items.Where(x => x.Container.ID == myContainerId)
.Where(x=> !IsNotWhatINeed(x));
The other answers are correct in that you can further refine the query with a 'where' statement. However, I'm assuming your query is a Linq2Sql query. So you need to make sure you have the data in memory before further filtering with a custom function:
var items = MyDataContext.Items.Where(x => x.Container.ID == myContainerId)
.ToList(); // fetch the data in memory
var itemsToRemove = items.Where(IsNotWhatINeed);
If you really want to extend the IQueryable, then the 'IsNotWhatINeed' function must be translated to something that Linq2Sql understands.
Try This:
var items = YourDataContext.Items.Where(x => x.Container.ID == myContainerId
&& !IsNotWhatYouNeed(x));
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