我有以下方式的数据....GROUP BY
ColumnA ColumnB 7675 22838 7675 24907 7675 NULL
我想在下面的方式,结果.....
ColumnA ColumnB 7675 2 (need total count for Not Null value) 7675 0 (need count 0 for NULL value)
我有以下方式的数据....GROUP BY
ColumnA ColumnB 7675 22838 7675 24907 7675 NULL
我想在下面的方式,结果.....
ColumnA ColumnB 7675 2 (need total count for Not Null value) 7675 0 (need count 0 for NULL value)
select columnA,
count(columnB) as non_null_count,
sum(columnB is null) as null_count
from your_table
group by ColumnA
SELECT ColumnA, COUNT(ColumnB) ColumnB
FROM YourTable
GROUP BY ColumnA
UNION ALL
SELECT ColumnA, 0
FROM YourTable
WHERE ColumnB IS NULL
GROUP BY ColumnA
你可以很容易地做一个计数和总和,这可能会更快,如果有很多的行,而不是选择所有的行两次与UNION
SELECT columna, columnb, SUM(mycount)
FROM
( SELECT *, COUNT(columnb) as mycount
FROM test
GROUP BY columnb
)t
GROUP BY mycount
ORDER BY CASE WHEN mycount = 0 THEN 1 ELSE 2 END DESC;
你可以引入一个计算列表示ColumnB
是否为空或不与ColumnA
一起使用它作为一个分组标准:
SELECT
t.ColumnA,
ColumnB = COUNT(t.ColumnB)
FROM
dbo.YourTable AS t
CROSS APPLY
(SELECT CASE WHEN t.ColumnB IS NULL THEN 1 ELSE 0 END) AS x (SubGroup)
GROUP BY
t.ColumnA,
x.SubGroup
ORDER BY
t.ColumnA,
x.SubGroup
;
的COUNT(t.ColumnB)
表达式将始终为NULL的空子组,并且对于相应的非空子组,它将返回非空条目的数量。
我喜欢你将null和非null计数分隔到不同列的方式......这不会产生@jitendra所要求的结果,但它可以说比他/她想到的结果更好。 – evanv 2014-10-06 17:28:40