How to retrieve stored image in sql database in asp.net mvc3?

Question

I have a table in my database and one of its columns is in Image data type. I can store Image in database but I can't retrieve it. I want to retrive Image for each logged in user. I used this code:

public ActionResult ShowImage()
{
    var userID = GetUserID();
    var advert = from ad in StoreDb.Ads where ad.UserId == userID select ad.AdImage;
    return File(advert, "Image");     
}

But got this error:

Error 2 Argument 1: cannot convert from 'System.Linq.IQueryable' to 'string' C:\Users\Tena\Documents\Visual Studio 2010\Projects\MvcApplication6\MvcApplication6\Controllers\Default3Controller.cs 92 25 MvcApplication6

The problem is that advert is in

System.Linq.IQueryable<>byte[]

format but File needs byte[] format. What should I do now? Any answer is helpful.

Thanks

Tom Chantler · Accepted Answer · 2012-06-01 11:44:03Z

2

The problem is that the LINQ query isn't being evaluated and the query as it stands could theoretically return more than one result (hence it's an IQueryable).

In fact the query doesn't look right as presumably there will be more than one advert for a particular user and I wouldn't expect the adverts to be stored according to user in any case, but I don't know anything about your data structure, so I'll just try to help you make the query work and you can refine it later.

Try changing this line:

var advert = from ad in StoreDb.Ads where ad.UserId == userID select ad.AdImage;

to this:

var advert = (from ad in StoreDb.Ads where ad.UserId == userID select ad.AdImage).FirstOrDefault();

I could give you other tips around how to do this, but try that first and see what happens.

edited Jun 1, 2012 at 11:44

answered Jun 1, 2012 at 11:38

Tom Chantler

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3 Comments

starrr Over a year ago

Thank you very much. yes it was my fault. There were more than one image for user, When I deleted them from databse it works perfect.

starrr Over a year ago

Is there better way to do this?

Tom Chantler Over a year ago

Other than making a generic file retrieval function that takes an ID and gets the file, your method actually looks fine. I have bits of code like this in my MVC projects: return File(file.ImageData, file.MimeType); It might be helpful to give your controllers more meaningful names (the error message contains a reference to Default3Controller.cs).

Mithrandir · Accepted Answer · 2012-06-01 11:35:24Z

2

I'not sure, this is the way to go for this problem. I usually implement a custom http handler, which expects some id (e.g. userid), connects to the database, fetches the picture and returns a stream of bytes with the correct mime type of the picture.

In the "view" i just create an image tag with the url of the http handler as image source.

answered Jun 1, 2012 at 11:35

Mithrandir

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1 Comment

starrr Over a year ago

@ Mithrandir: Thank for your answer, but I'm new in mvc and didn't work with this solution yet. But Thank you and I will learn it.

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