在SQL分組空和空值作爲一個

Question

我有一個查詢，其提供在數據庫中用於事物不同類別的細分：

select categories, count(*) from products 
group by categories 

的有關資料是這樣的：

NULL    56 
        42 
FooCategory   12 
BlahCategory  2 

我想團體NULL和<blank>

NoCategory   98 
FooCategory   12 
BlahCategory  2 

Answer 1

嘗試

select categories, 
case when categories is null or categories = ' ' 
then 'noCategory' else categories end as grouped, 
count(*) 
from products 
group by grouped 

Answer 2

嘗試

select ISNULL(categories,'') as Categories, count(*) from products 
group by ISNULL(categories,'') 

UPDATE

在這裏看到參數所需

ISNULL (check_expression , replacement_value)