EF 5.0 Simple Delete Statement

Question

I'm trying to run a delete statement on EF 5.0. that deletes let say 5000 ~ 40000 records here is my code:

using(myEntity ctx = new myEntity) {
var q = from s in ctx.MyTable.where( x => x.accountID == 1234) select s;
ctx.myTable.Remove(q);     
// because there is no ctx.DeleteObject(whatever) 
// since this is not EF 4.0
}

and here is the error: cannot convert from 'System.Linq.IQueryable' to 'namespace.myTable'

any idea?

possible duplicate of [Bulk-deleting in LINQ to Entities](http://stackoverflow.com/questions/869209/bulk-deleting-in-linq-to-entities) — Vulcronos, Sep 18 '13 at 17:43

jclake · Answer 1 · 2013-09-18T18:45:20.847

In your example, you are getting an IQueryable< myTable > and trying to pass it into a Remove method with the following signature:

public TEntity Remove(TEntity entity)

Since it only accepts an instance of an entity, you must actually convert the IQueryable to a list of entities and then iterate through them. I would most likely do it as follows myself:

using(var ctx = new myEntity())
{
    ctx.myTable
       .Where(x => x.accountId == 1234)
       .ToList()
       .ForEach(item => ctx.myTable.Remove(item));

    ctx.SaveChanges();
}

Captain Kenpachi · Accepted Answer · 2013-09-19T07:31:19.543

0

You are trying to remove a LINQ query from your table (which makes no sense), as opposed to removing a table entry.

What you need to do is either this:

using(myEntity ctx = new myEntity) {
    var q = from s in ctx.MyTable.where( x => x.accountID == 1234) select s;
    foreach(var entry in q)
    {
        ctx.myTable.Remove(entry);     
    }
}

Or write a stored procedure, import it into Entity Framework and execute it.

edited Sep 19 '13 at 07:31

answered Sep 18 '13 at 17:49

Captain Kenpachi

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3

`.ToList()` is not needed. – King King Sep 18 '13 at 17:50
seriously? so the only way to delete 3 rows is to manually loop through the collection? and LINQ can only handle deletion of a single record? – Sash the man Sep 18 '13 at 17:59
1

@Sashtheman because `LINQ` is for `querying`, not for `modifying, deleting, ...`, it's just used to **prepare** some collection before you do something with that collection. – King King Sep 18 '13 at 18:08
1

The right way to bulk delete entries from a table is to write a stored procedure. – Captain Kenpachi Sep 19 '13 at 07:32

EF 5.0 Simple Delete Statement

2 Answers2