I get the error “Cannot call methods on nvarchar” why?

Question

Hi guys I have written this stored procedure but there is an error in it that says

Cannot call methods on nvarchar

T-SQL code:

ALTER PROCEDURE dbo.User_Announcement_Create
        @Announcement nvarchar(250),
        @UserName nvarchar(256)
AS
BEGIN
    DECLARE @NewAnnouncement nvarchar(250)
    SELECT @NewAnnouncement = NULL

    IF( @UserName.dbo.Announcements IS NULL )
       ( SELECT UserName FROM dbo.aspnet_Users
         WHERE @UserName = UserName ) 
       RETURN -1
END

DECLARE @CreateAnnouncement bit

DECLARE @ReturnValue   int
SET @ReturnValue = 0

SELECT @NewAnnouncement = Announcement FROM Announcements

SET @CreateAnnouncement = 1

INSERT INTO Announcements (Announcement, UserName)
VALUES (@Announcement, @UserName)

Can anyone help me fix this problem please?

Answer 1

Replace this part

IF( @UserName.dbo.Announcements IS NULL ) -- not understandable what are you doing here

with this

IF( @UserName IS NULL )