## Question:

Below is the SQL I use to create my pivot table. I need to replace null values with ‘0’, however, I get an error when trying to use a case expression inside the pivot. Is this not possible?```
SELECT *
FROM
(
SELECT c.CompanyName, p.ProductName, od.Quantity
FROM Customers as c INNER JOIN
Orders as o ON c.CustomerID = o.CustomerID INNER JOIN
[Order Details] as od ON o.OrderID = od.OrderID INNER JOIN
Products as p on od.ProductID = p.ProductID
) as QuantityOrdered
pivot
(
(CASE
WHEN SUM(Quantity) is NULL THEN 0
ELSE SUM(Quantity)
END)
for ProductName in ([Alice Mutton],
[Aniseed Syrup],
[Boston Crab Meat],
[Camembert Pierrot],
[Carnarvon Tigers])
) as crossTabTable
order by CompanyName
```

## Answer:

`PIVOT`

only allows simple aggregation functions and a single column, no other expressions.You can instead use conditional aggregation, which is more wordy but much more flexible.

```
SELECT
c.CompanyName,
[Alice Mutton] = ISNULL(SUM(CASE WHEN p.ProductName = 'Alice Mutton' THEN od.Quantity END), 0),
[Aniseed Syrup] = ISNULL(SUM(CASE WHEN p.ProductName = 'Aniseed Syrup' THEN od.Quantity END), 0),
[Boston Crab Meat] = ISNULL(SUM(CASE WHEN p.ProductName = 'Boston Crab Meat' THEN od.Quantity END), 0),
[Camembert Pierrot] = ISNULL(SUM(CASE WHEN p.ProductName = 'Camembert Pierrot' THEN od.Quantity END), 0),
[Carnarvon Tigers] = ISNULL(SUM(CASE WHEN p.ProductName = 'Carnarvon Tigers' THEN od.Quantity END), 0)
FROM Customers as c
INNER JOIN Orders as o ON c.CustomerID = o.CustomerID
INNER JOIN [Order Details] as od ON o.OrderID = od.OrderID
INNER JOIN Products as p on od.ProductID = p.ProductID
GROUP BY
c.CompanyName
ORDER BY
c.CompanyName;
```

If you have better answer, please add a comment about this, thank you!