Question

我在SQL Server中有两个字符串。

例如：

declare @str1 as varchar(max)
declare @str2 as varchar(max)

set @str1 ='10:00am,2:00pm'

set @str2 = '10:00am,12:00pm,2:00pm,4:00pm,6:00pm,8:00pm'

我希望比较两个字符串，并希望从@str2获取那些不在@str1中的字符串。

这意味着结果应为：

@str3 = '12:00pm,4:00pm,6:00pm,8:00pm'

Answer 1

试试这个： -

declare @str1 as varchar(max)
declare @str2 as varchar(max)

set @str1 ='10:00am,2:00pm'
set @str2 = '10:00am,12:00pm,2:00pm,4:00pm,6:00pm,8:00pm'

--the below 2 CTE's are used for splitting the string into different rows
;with cteStr1(str1) as
(
 SELECT
 RIGHT(LEFT(@str1,Number-1),
 CHARINDEX(',',REVERSE(LEFT(','+@str1,Number-1)))) as str1
 FROM
 master..spt_values
 WHERE
 Type = 'P' AND Number BETWEEN 1 AND LEN(@str1)+1
 AND
(SUBSTRING(@str1,Number,1) = ',' OR SUBSTRING(@str1,Number,1)  = '') 
),cteStr2(str2) as
  (
   SELECT
   RIGHT(LEFT(@str2,Number-1),
   CHARINDEX(',',REVERSE(LEFT(','+@str2,Number-1)))) as str2
   FROM
   master..spt_values
   WHERE
   Type = 'P' AND Number BETWEEN 1 AND LEN(@str2)+1
   AND
  (SUBSTRING(@str2,Number,1) = ',' OR SUBSTRING(@str2,Number,1)  = '') 
  )
  Select str2 from cteStr2 
  except
  select str1 from cteStr1

Answer 2

试试这个

DECLARE @str1 VARCHAR(MAX)
DECLARE @str2 VARCHAR(MAX)

SET @str1 ='10:00am,2:00pm'
SET @str2 = '10:00am,12:00pm,2:00pm,4:00pm,6:00pm,8:00pm'

SET @str1 = ',' + @str1 + ','
SET @str2 = ',' + @str2 + ','

DECLARE @name NVARCHAR(255)
DECLARE @pos INT

WHILE CHARINDEX(',', @str1) > 0
BEGIN
    SELECT @pos  = CHARINDEX(',', @str1)  
    SELECT @name = SUBSTRING(@str1, 1, @pos-1)

    SELECT @str1 = SUBSTRING(@str1, @pos+1, LEN(@str1)-@pos)
    IF @name <> ''
    BEGIN
        SET @str2 =  REPLACE(@str2,','+@name,'')
    END
END

 SET @str2 =  REPLACE(@str2,','+@name,'')

SELECT SUBSTRING(@str2, 2, LEN(@str2)-2) AS Result

Answer 3

试试这个 -

DECLARE 
      @str1 VARCHAR(500)
    , @str2 VARCHAR(500)

SELECT 
      @str1 = '10:00am,2:00pm'
    , @str2 = '10:00am,12:00pm,2:00pm,4:00pm,6:00pm,8:00pm'

;WITH cte AS
(
    SELECT 
          id = p.value('(./n)[1]', 'INT')
        , tm = p.value('(./s)[1]', 'VARCHAR(500)')
    FROM (
        SELECT field = CAST('<r><s>' + REPLACE(SUBSTRING(t.string + ',', 1, LEN(t.string + ',')), ',', '</s><n>' + CAST(t.id AS VARCHAR(10)) + '</n></r><r><s>') + '</s></r>' AS XML) 
        FROM (
            SELECT string = @str1, id = 1
            UNION ALL
            SELECT @str2, 2
        ) t
    ) d
    CROSS APPLY field.nodes('/r') t(p)
    WHERE t.p.exist('n') = 1
)
SELECT tm FROM cte WHERE id = 2
EXCEPT
SELECT tm FROM cte WHERE id = 1

或试试这个 -

;WITH cte2 AS
(
SELECT 
      t.id
    , tm = 
        SUBSTRING(
              ',' + t.string + ','
            , number + 1
            , CHARINDEX(',', ',' + t.string + ',', number + 1) - number - 1)
FROM (
    SELECT string = @str1, id = 1
    UNION ALL
    SELECT @str2, 2
) t
CROSS JOIN [master].dbo.spt_values n
WHERE [type] = 'p'
    AND number <= LEN(',' + t.string + ',') - 1
    AND SUBSTRING(',' + t.string + ',', number, 1) = ','
)
SELECT tm FROM cte2 WHERE id = 2
EXCEPT
SELECT tm FROM cte2 WHERE id = 1

如何比较SQL Server中的两个字符串元素

3 个答案: