TSQL在字符串位置按位置计数“ 1”

Question

有这样的类别的字段：

如果将字符串设置为“ 1”，则该字符串中的每个位置代表“ 101011111000000101010011000101 ...”。 因此，“ 1”表示已设置，而“ 0”表示未设置。 我想计算具有最高“ 1”数量的类别，并按降序排列。

我当前的解决方案是这样的：

SELECT COUNT(SUBSTRING([Interests], 1, 1)) AS xcount, 1 AS ID
FROM [db1].[dbo].[Contacts]
WHERE SUBSTRING([Interests], 1, 1) = '1'
UNION
SELECT COUNT(SUBSTRING([Interests], 2, 1)) AS xcount, 2 AS ID
FROM [db1].[dbo].[Contacts]
WHERE SUBSTRING([Interests], 2, 1) = '1'
UNION
SELECT COUNT(SUBSTRING([Interests], 3, 1)) AS xcount, 3 AS ID
FROM [db1].[dbo].[Contacts]
WHERE SUBSTRING([Interests], 3, 1) = '1'
UNION
SELECT COUNT(SUBSTRING([Interests], 4, 1)) AS xcount, 4 AS ID
FROM [db1].[dbo].[Contacts]
WHERE SUBSTRING([Interests], 4, 1) = '1'
UNION
SELECT COUNT(SUBSTRING([Interests], 5, 1)) AS xcount, 5 AS ID
FROM [db1].[dbo].[Contacts]
WHERE SUBSTRING([Interests], 5, 1) = '1'
ORDER BY xcount DESC

有没有更好或更快速的方法来计算这些类别？

Answer 1

SELECT SUM(CASE WHEN SUBSTRING([Interests], _ID.ID, 1) = '1' THEN 1 ELSE 0 END) AS xcount, _ID.ID
FROM [db1].[dbo].[Contacts], (VALUES (1),(2),(3),(4),(5)) AS _ID(ID)
GROUP BY _ID.ID
ORDER BY xcount DESC

对于更多类别，只需增加_ID序列即可。

Answer 2

这将计算由0和1组成的字符串中的数字“ 1”

declare @s varchar(100) ='101011111000000101010011000101';
select cnt = len(@s) - len(replace(@s,'0',''))