转换ObjectResult <int?> 进入清单 <int>

Question

I have written a stored procedure :-

CREATE PROCEDURE GET_USERSTORYDATA_EXISTS
    @MyWizardUserStoryId INT
   ,@ProjectId INT
   ,@StoryTitle NVARCHAR(MAX)
AS
BEGIN
    SET NOCOUNT ON;
    IF EXISTS (SELECT 1 FROM USERSTORY WHERE [MyWizardUserStoryId]=@MyWizardUserStoryId AND ProjectId=@ProjectId)
    BEGIN
        IF EXISTS (SELECT 1 FROM USERSTORY WHERE [MyWizardUserStoryId]=@MyWizardUserStoryId AND ProjectId=@ProjectId AND Title=@StoryTitle)
        BEGIN
            SELECT 0;
        END
        ELSE
         BEGIN
            SELECT 1;
        END
    END
    ELSE
         BEGIN
            SELECT 1;
        END

END
GO

I have consumed this procedure via Entity framework :-

List<Int32>lst=context.GET_USERSTORYDATA_EXISTS(MyWizardUserStoryId,ProjectId,storyTitle);

but its giving me error:-

Can not implicitly convert type 'ObjectResult<int?>' to List<int>

Answer 1

Since ObjectResult<T> implements IEnumerable<T> you can use ToList . However, you also need to convert from nullable int. Easiest way would be to project using a Linq Select and then ToList . This code will replace any null values with zero:

List<Int32> lst = context
    .GET_USERSTORYDATA_EXISTS(MyWizardUserStoryId, ProjectId, storyTitle)
    .Select(i => i.GetValueOrDefault(0))
    .ToList();

Answer 2

要将对象结果转换为列表，我将添加ToList（），但是在您的情况下，我认为它不起作用，因为您只从存储过程中返回了一个整数。

Answer 3

List<Int32?> list1 =new List<int?>() { 1, null, 2 };
                List<Int32> list2 = new List<int>();
                foreach (var item in list1)
                {
                    if (item.HasValue)
                        list2.Add(item.Value);
                }