sql-server - 如何比较两个逗号分隔的字符串，如果至少有 1 个匹配则返回 TRUE

Question

我必须包含逗号分隔字符串的变量：

@v1 = 'hello, world, one, two'
@v2 = 'jump, down, yes, one'

如果至少有一个匹配项，我需要一个返回 TRUE 的函数。所以在上面的例子中，它会返回 TRUE，因为值 'one' 在两个字符串中。

这在 SQL 中可能吗？

Answer 1

Use a split function (many examples here - CLR is going to be your best option in most cases back before SQL Server 2016 - now you should use STRING_SPLIT()).

Once you have a split function, the rest is quite easy. The model would be something like this:

DECLARE @v1 VARCHAR(MAX) = 'hello, world, one, two',
        @v2 VARCHAR(MAX) = 'jump, down, yes, one';

SELECT CASE WHEN EXISTS 
(
  SELECT 1 
    FROM dbo.Split(@v1) AS a
    INNER JOIN dbo.Split(@v2) AS b
    ON a.Item = b.Item
)
THEN 1 ELSE 0 END;

You can even reduce this to only call the function once:

SELECT CASE WHEN EXISTS 
(
  SELECT 1 FROM dbo.Split(@v1)
  WHERE ', ' + LTRIM(@v2) + ',' 
    LIKE '%, ' + LTRIM(Item) + ',%'
) THEN 1 ELSE 0 END;

On 2016+:

SELECT CASE WHEN EXISTS 
(
  SELECT 1 FROM STRING_SPLIT(@v1, ',')
  WHERE ', ' + LTRIM(@v2) + ',' 
    LIKE '%, ' + LTRIM([Value]) + ',%'
) THEN 1 ELSE 0 END;

Answer 2

您可以使用 CTE 将字符串拆分为 xml 节点，然后将单词插入表变量中。加入表变量将显示任何匹配项

DECLARE @v1 VARCHAR(200) = 'hello, world, one, two'
DECLARE @v2 VARCHAR(200) = 'jump, down, yes, one'
DECLARE @v1Words TABLE (word VARCHAR(100))
DECLARE @v2Words TABLE (word VARCHAR(100))

;WITH cteSplitV1 AS( 
SELECT CAST('<word>' + REPLACE(@v1,', ','</word><word>') + '</word>' AS XML) AS words) 
INSERT INTO @v1Words(word)
    SELECT word.x.value('.','VARCHAR(100)') AS [word]
    FROM cteSplitV1
    CROSS APPLY words.nodes('/word') AS word(x)

;WITH cteSplitV2 AS( 
SELECT CAST('<word>' + REPLACE(@v2,', ','</word><word>') + '</word>' AS XML) AS words) 
INSERT INTO @v2Words(word)
    SELECT word.x.value('.','VARCHAR(100)') AS [word]
    FROM cteSplitV2 
    CROSS APPLY words.nodes('/word') AS word(x)

SELECT *
FROM @v1Words v1
JOIN @v2Words v2
    ON v1.word = v2.word