CODEWITHSUNDEEP
linq-to-sqlarraysiqueryabletype-conversion
perlynsparks
perlynsparks

Reputation: 401

how to convert type 'system.linq.iqueryable<byte[]>' to 'byte[]'

In Linq to SQL asp.net, I want to fetch a specific image from database and display on an aspx page. I declared returned type as "var" on the code. So after fetching the image, it assigns image to var type.

Here is the code:

var db = from c in context.Images
                         where c.imageId == iID
                         select c.imageData;
return new MemoryStream((byte[])db);  ---->> this line of code gives error

It gives this compile error: Cannot convert type 'system.linq.iqueryable' to 'byte[]'.

How can I convert 'system.linq.iqueryable type to byte[] ?

Upvotes: 0

Views: 2977

Answers (2)

Kiran.Bakwad
Kiran.Bakwad

Reputation: 624

try below line this work for me

var db = (context.Images.FirstOrDefault(i => i.imageId == ID).ImageData

Upvotes: 1

Justin Niessner
Justin Niessner

Reputation: 245479

Your problem is that you're selecting a collection of byte[] rather than a single byte[].

Depending on the behavior you want for your application, you can use Single, SingleOrDefault, First, or FirstOrDeault:

var image = context.Images.FirstOrDefault(i => i.imageId == ID);
if(image == null)
{
    // Handle the case where no image was found.
    //
    // First or Single would throw Exceptions in this case
    // if that's what you want.
}
else
{
    return new MemoryStream(image.imageData);
}

Upvotes: 3

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