a为空的元素个数:

select count(a) from us where a is null;

a不为空的元素个数:

select count(a) from us where a is not null;

SELECT SUM(NULLs) AS 'NULLS', SUM(NOTNULLs) AS 'NOTNULLs' FROM 
    (select count(*) AS 'NULLs', 0 as 'NOTNULLs' FROM us WHERE a is null
    UNION select 0 as 'NULLs', count(*) AS 'NOTNULLs' FROM us WHERE a is not null) AS x

这很糟糕，但它将返回一个带有2个cols的记录，指示null和非null的计数。

用于计数非空值

select count(*) from us where a is not null;

用于计算空值

 select count(*) from us where a is null;

Try

SELECT 
   SUM(ISNULL(a)) AS all_null,
   SUM(!ISNULL(a)) AS all_not_null
FROM us;

简单!

试试这个. .

SELECT CASE 
         WHEN a IS NULL THEN 'Null' 
         ELSE 'Not Null' 
       END a, 
       Count(1) 
FROM   us 
GROUP  BY CASE 
            WHEN a IS NULL THEN 'Null' 
            ELSE 'Not Null' 
          END 

a为空的元素个数:

select count(a) from us where a is null;

a不为空的元素个数:

select count(a) from us where a is not null;