我想计算多列中的不同值并在单独的行中显示结果

Question

我是 SQL 的新手，正在处理一个数据集，我需要在每个列中计算 1,0 或 Y,N 标志并给出结果计数列。举个例子，这是数据的样子：

Flag1	Flag2	Flag3	Flag4
N	Y	N	Y
Y	Y	Y	Y
N	N	N	N
Y	Y	N	N

这是我想要的：

Flag1	Flag2	Flag3	Flag4	COUNT
N				2
Y				2
	N			1
	Y			3
		N		3
		Y		1
			N	2
			Y	2

Answer 1

您只需要所有可能组合之间的并集：

select 'N' as Flag1, NULL as Flag2, NULL as Flag3, NULL as Flag4, (select count(*) from table_name where Flag1='N') as count
union all
select 'Y', NULL, NULL, NULL, (select count(*) from table_name where Flag1='Y') as count

union all

select NULL, 'N', NULL, NULL, (select count(*) from table_name where Flag2='N') as count
union all
select NULL, 'Y', NULL, NULL, (select count(*) from table_name where Flag2='Y') as count

union all

select NULL, NULL, 'N', NULL, (select count(*) from table_name where Flag3='N') as count
union all
select NULL, NULL, 'Y', NULL, (select count(*) from table_name where Flag3='Y') as count

union all

select NULL, NULL, NULL, 'N', (select count(*) from table_name where Flag4='N') as count
union all
select NULL, NULL, NULL, 'Y', (select count(*) from table_name where Flag4='Y') as count

Answer 2

使用 GROUP BY GROUPING SETS 函数有一种更简单的计算方法：

WITH sample_data AS (
  SELECT * 
    FROM (VALUES 
  ('N', 'Y', 'N', 'Y'),
  ('Y', 'Y', 'Y', 'Y'),
  ('N', 'N', 'N', 'N'),
  ('Y', 'Y', 'N', 'N')) T(Flag1, Flag2, Flag3, Flag4)
)
SELECT Flag1, Flag2, Flag3, Flag4, COUNT(*) AS COUNT
  FROM sample_data
 GROUP BY GROUPING SETS (Flag1, Flag2, Flag3, Flag4)
 ORDER BY Flag1, Flag2, Flag3, Flag4;

结果：

FLAG1	FLAG2	FLAG3	FLAG4	COUNT
N				2
Y				2
	N			1
	Y			3
		N		3
		Y		1
			N	2
			Y	2

我想计算多列中的不同值并在单独的行中显示结果

I want to count distinct values in multiple column and show the results in separate rows

sql

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