Null reference exception getting from method

Question

I'm using SQLHELPER classes for getting the id from the procedure. I had written the following code :

string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
public int CheckUser(string userName,string password)
    {
        SqlParameter[] spc = new SqlParameter[5];
        spc = SqlHelperParameterCache.GetSpParameterSet(constr, "CheckUser");
        spc[0].Value = userName;
        spc[1].Value =password;
        spc[2] = new SqlParameter("@userExist", SqlDbType.Int, 32);
        spc[2].Direction = ParameterDirection.Output;
        int res = (int)SqlHelper.ExecuteScalar(constr, CommandType.StoredProcedure, "CheckUser", spc);

        return res;
    }

I'm pssing the username and password but I'm facing "Null reference exception was unhandled by the user" run time exception. When I debug I got the both values which I sent exactly.

Create proc CheckUser
@userName varchar(50),
@password varchar(50),
@userExist int output
as
  begin
   set @userExist= (select COUNT(*) 
                from tbluserInfo 
                where  UserName=@userName and [Password]=@password)

    select [uid] from tbluserInfo 
            where  UserName=@userName and [Password]=@password

 end

Null Ref QuickWatch. Click here for image

Possible duplicate of [What is a NullReferenceException, and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — sujith karivelil, Mar 29 '17 at 05:42
you have take `SqlParameter[5]` so length is 5 and pass only 3 parameters is there any reason behind this? — Curiousdev, Mar 29 '17 at 05:54
@Curiousdev ,Thanks for that. I replaced it to 3, but still the exception is raising. — Srikanth Reddy, Mar 29 '17 at 05:59
ohh ohkk one more thing can you please check is `SqlHelper.ExecuteScalar(constr, CommandType.StoredProcedure, "CheckUser", spc)` this giving a value or null ? it may be cause the issue — Curiousdev, Mar 29 '17 at 06:03
@Curiousdev , It's return type is object itself. giving means you mean any other than return type ? — Srikanth Reddy, Mar 29 '17 at 06:06
set @userExist= (select isnull(COUNT(*),0) from tbluserInfo where UserName=@userName and [Password]=@password) check this please — Murad, Mar 29 '17 at 06:06
If @userExist is null then (int)SqlHelper.ExecuteScalar(constr, CommandType.StoredProcedure, "CheckUser", spc); this line will return Null reference exception — Murad, Mar 29 '17 at 06:22
Might be, It's an output parameter. How can I handle it then ? — Srikanth Reddy, Mar 29 '17 at 06:28

Curiousdev · Answer 1 · 2017-03-29T06:36:39.053

0

You have to return @userExist which you have set from SP please find below updated SP

UPDATED

Create proc CheckUser
@userName varchar(50),
@password varchar(50),
@userExist int output
as
  begin
   set @userExist= (select isnull([uid],0) from tbluserInfo 
            where  UserName=@userName and [Password]=@password)

   return @userExist;

 end

edited Mar 29 '17 at 06:36

answered Mar 29 '17 at 06:07

Curiousdev

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returned the output parameter, still facing the same issue. I'm getting null reference exception not sqlexception. Please think in that way also. – Srikanth Reddy Mar 29 '17 at 06:16
PLease put a debug point and than quick watch on `SqlHelper.ExecuteScalar(constr, CommandType.StoredProcedure, "CheckUser", spc)` this line what you'r getting check if debug reached at this line or not if not which line you'r getting exception – Curiousdev Mar 29 '17 at 06:20
I'm getting Null in quickwatch. Please check the image I had attached below the Quest. – Srikanth Reddy Mar 29 '17 at 06:27
Ohh that's weird can you show the `SqlHelper.ExecuteScalar` method? – Curiousdev Mar 29 '17 at 06:55

Null reference exception getting from method

1 Answers1