LINQ to SQL . how to select all record using .take()

Question

var result=(from refridgerators in context.A                                               
                                     group refridgerators by new { refridgerators.Id, refridgerators.Name } into gr
                                     select new DAO<String>
                                     {
                                         Key = gr.Key.Name,
                                         Count = gr.Count()
                                     }).OrderByDescending(k => k.Count).Take(numberOfRecords).ToList();

This is my linq to sql query this is working perfectly fine.

this shows top 5 records (sorted by their count) if i pass numberOfRecords =5.

now my problem is i don`t want to modify query. so what should i do in above query to show all records. This is in relation with my requirement i want to use same query to show all refridgerators and Top 5 , top 10 refridgerators.

I am not sure if it is possible using LINQ. but i guess there must be something related to this.

Solution 1

As the right solution has already been posted by Tim, still I want your attention to the simpler solution, if suits to your requirement. Add one more if condition at the top of this query.

if(allRecordRequired)
{
  numberOfRecords = 2000000;
}

Leave your query as it is.

Solution 2

I would simply don't add the Take to the query but to the code where you consume this query.

So for example:

public static IEnumerable<DAO> GetRefrigerators()
{
    var query = from refridgerators in context.A                                               
                group refridgerators by new { refridgerators.Id, refridgerators.Name } into gr
                select new DAO<String>
                {
                     Key = gr.Key.Name,
                     Count = gr.Count()
                };
    return query.OrderByDescending(k => k.Count);
}

Now you can either use:

var refrigerators = GetRefrigerators().Take(5).ToList();

or

var refrigerators = GetRefrigerators().Take(10).ToList();

or

var refrigerators = GetRefrigerators().ToList();

Solution 3

I'd make numberOfRecords a int? and if the value is null you should not call Take(numberOfRecords)

var result = (from refridgerators in context.A
              group refridgerators by new { refridgerators.Id, refridgerators.Name } into gr
              select new DAO<String>
              {
                 Key = gr.Key.Name,
                 Count = gr.Count()
              }).OrderByDescending(k => k.Count);

if(numberOfRecords.HasValue)
    result = result.Take(numberOfRecords.Value);

return result.ToList();

I know it changes your query a little bit but I believe it is pretty acceptable, adding a numberOfRecords of a super high value adds an overheard to your query which isn't useful in your case.

Solution 4

So this post is very old, I know, but my solution is not provided (maybe someone wants to achieve the same after 2 years, like me):

You could create your own extension-method that also works with linq 2 sql. Example:

public static class LinqExtensions
{
    public static IEnumerable<TResult> TakeIfNotNull<TResult>(this IEnumerable<TResult> source, int? count)
    {
        return !count.HasValue ? source : source.Take(count.Value);
    } 
}

this takes an int? instead of int and returns either the source-enumerable if count is null else it returns the result of default Take-method.

So you could write like:

.OrderByDescending(k => k.Count).TakeIfNotNull(numberOfRecords).ToList();

if numberOfCounts is null, it'll take all records.

Solution 5

Pass a huge number to your method.A number that is equal (at least) or bigger than the items count.That should give you all records.

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