How to pass null to int column in linq

Question

How to pass null to int column in linq

How to assign null to int column in LINQ. eg.

 SQLDBDataContext sqlD = new SQLDBDataContext();
 var result = from p in sqlD.loadsRadius(Convert.ToInt32(Request["radius"]), .....

here, if Request ["radius"] is null, throws an error.

I could go through 0, but I need to change in many of the already existing routines.

Thanks in advance. Anil

+1

int linq nullable

anil Dec 10. '08 at 13:09

source to share

5 answers

Aaron powell · Answer 1 · 2008-12-12T05:34:42+0000

You need to cast int to null, for example:

var result = from p in sqlD.loadsRadius(string.IsNullOrEmpty(Request["radius"]) ? (int?)null : int.Parse(Request["radius"]);

CodeChef · Answer 2 · 2008-12-10T13:58:23+0000

If the exception is a FormatException, I assume that the value returned by Request ["radius"] is in fact the string "null". If Request ["radius"] actually returned null, Convert.ToInt32 () will return zero. You can try using with int.TryParse () to avoid the exception.

Pradeep kumar mishra · Answer 3 · 2008-12-10T14:09:18+0000

as suggested by Codechef ..

int radius = -1;
int.TryParse(Request["radius"],out radius)
if(radius > 0) // you can remove this clause if you don't want this
{
SQLDBDataContext sqlD = new SQLDBDataContext();
 var result = from p in sqlD.loadsRadius(radius)
}

TGnat · Answer 4 · 2008-12-10T14:35:21+0000

Look at nullable types: Here.

0

TGnat Dec 10. '08 at 14:35

source to share

Alexander Prokofyev · Answer 5 · 2008-12-12T05:34:14+0000

Can you use ?? operator :

Convert.ToInt32(Request["radius"] ?? "0")

If Request ["radius"] is null, it will return "0" instead.

How to pass null to int column in linq

More articles: