如何计算sql中零的数量？

Question

我有一列的值为 0 或 1。我如何计算零的数量？

SELECT A.id
FROM table1 A
GROUP BY A.id
HAVING SUM(A.zeroorone) >=
ALL (SELECT SUM(AA.zeroorone)
    FROM table1 AA
    GROUP BY AA.id)

我知道这计算的数量。 我似乎无法得到它

Answer 1

CASE 语句会做得很好：

SELECT SUM(CASE WHEN zeroorone = 0 
                THEN 1 
                ELSE 0 END) AS TOTAL_ZEROS
  FROM table1 

Answer 2

使用计数...

SELECT COUNT(*) FROM table1 
WHERE zeroone=0

Answer 3

如果您只想要表中零的计数，请使用以下命令：

SELECT COUNT(1) AS COUNT_OF_ZEROES
FROM table1
WHERE zeroone = 0

如果您想要每个 id 的计数，请使用它。

SELECT id, COUNT(1) AS COUNT_OF_ZEROES
FROM table1
WHERE zeroone = 0
GROUP BY id

Answer 4

我知道这很重要

你确定吗？ 在我看来，它返回id s，其中它的计数大于或等于它的零计数。

如果您对查询执行您想要的操作感到高兴，但您想要反转效果——例如返回id s，其中它的零计数大于或等于它的计数——那么只需更改比较运算符：

SELECT A.id
FROM table1 A
GROUP BY A.id
HAVING SUM(A.zeroorone) <=  -- changed from >=
ALL (SELECT SUM(AA.zeroorone)
    FROM table1 AA
    GROUP BY AA.id)