Как я могу изменить ПУСТОЙ УКАЗАТЕЛЬ на 0 при получении единственного значения от функции SQL?
Вы можете создать new Date(/*...*/) на основе извлеченных данных из $http.get, например:
$scope.date = new Date('2013', '10', '28'); // for example
В любом случае вы можете увидеть эту демонстрацию в Plunker KBD>.
Надеюсь, это поможет вам.
5 ответов
Most database servers have a COALESCE function, which will return the first argument that is non-null, so the following should do what you want:
SELECT COALESCE(SUM(Price),0) AS TotalPrice
FROM Inventory
WHERE (DateAdded BETWEEN @StartDate AND @EndDate)
[edit]
Just to clarify things since there seems to be a lot of discussion about "COALESCE/ISNULL will still return NULL if no rows match", try this query you can copy-and-paste into SQL Server directly as-is:
SELECT coalesce(SUM(column_id),0) AS TotalPrice
FROM sys.columns
WHERE (object_id BETWEEN -1 AND -2)
Note that the where clause excludes all the rows from sys.columns from consideration, but the 'sum' operator still results in a single row being returned that is null, which coalesce fixes to be a single row with a 0.
I hope this helps explain it.
SELECT ISNULL(SUM(Price), 0) AS TotalPrice
FROM Inventory
WHERE (DateAdded BETWEEN @StartDate AND @EndDate)
That should do the trick.
Edit: Looks like everyone else beat me to it haha
Found the answer.
ISNULL() determines what to do when you have a null value.
In this case my function returns a null value so I needed specify a 0 to be returned instead.
SELECT ISNULL(SUM(Price), 0) AS TotalPrice
FROM Inventory
WHERE (DateAdded
BETWEEN @StartDate AND @EndDate)
SELECT 0+COALESCE(SUM(Price),0) AS TotalPrice
FROM Inventory
WHERE (DateAdded BETWEEN @StartDate AND @EndDate)
You could use
SELECT ISNULL(SUM(ISNULL(Price, 0)), 0).
I'm 99% sure that will work.