Question

如何用sql中的其他列相同位置特殊字符串替换特殊字符之间的缺失字符串？以下是示例

例如：

ColumnA                columnB        Output of columnb 
~as~df~gf~er            ~qw~~~          ~qw~df~gf~er
~Evening~Afternoon       ~~             ~Evening~Afternoon
~qw~dg~er~rt~yu~io~ty   ~df~~rt~~we~~   ~df~dg~rt~rt~we~io~ty

注意：两列特殊字符数相同。我需要像这样的列输出~qw~df~gf~er。我希望在特殊字符的所有缺失字符串中动态更改。请帮助我

Answer 1

您需要正确的功能，这很容易解决。例如，在我的数据库中，我有：

DECLARE @DataSource TABLE
(   
    [ColumnA] VARCHAR(1024)
   ,[ColumnB] VARCHAR(1024)
);

INSERT INTO @DataSource ([ColumnA], [ColumnB])
VALUES ('~as~df~gf~er', '~qw~~~')
      ,('~Evening~Afternoon', '~~')
      ,('~qw~dg~er~rt~yu~io~ty', '~df~~rt~~we~~');


SELECT DS.[ColumnA]
      ,DS.[ColumnB]
      ,[dbo].[ConcatenateWithOrderAndDelimiter] (A.[index], ISNULL(NULLIF(B.[value], ''), A.[value]), '~')
FROM @DataSource DS
CROSS APPLY [dbo].[fn_Utils_RegexSplitWithOrder] ([ColumnA], '~') A
LEFT JOIN
(
    SELECT [ColumnA]
          ,B.[index]
          ,B.[value]
    FROM @DataSource DS
    CROSS APPLY [dbo].[fn_Utils_RegexSplitWithOrder] ([ColumnB], '~') B
) B
    ON DS.[ColumnA] = B.[ColumnA]
    AND A.[index] = B.[index]
GROUP BY DS.[ColumnA]
        ,DS.[ColumnB];

所以，基本上你需要两个功能：

一个按值拆分字符串
一个用于字符串聚合（连接）

在我的情况下，我正在使用SQL CLR功能 - 您可以找到更多关于它们的here。

在SQL Server 2017中，我们可以使用STRING_AGG，在SQL Server 2016中，我们可以使用STRING_SPIT。

如果您不想浪费时间来实现SQL CLR功能，可以添加一个拆分功能（网络中有很多功能）。例如，我使用过这个：

CREATE FUNCTION [dbo].[fn_Analysis_ConvertCsvListToNVarCharTableWithOrder](@List nvarchar(max), @Delimiter nvarchar(10) = ',')
RETURNS @result TABLE 
(   
    [Value] nvarchar(max),
    [SortOrder] bigint NOT NULL
)
AS
BEGIN
    IF @Delimiter is null 
    BEGIN
        SET @Delimiter = ','
    END
    DECLARE @XML xml = N'<r><![CDATA[' + REPLACE(@List, @Delimiter, ']]></r><r><![CDATA[') + ']]></r>'

    DECLARE @BufTable TABLE (Value nvarchar(max), SortOrder bigint NOT NULL IDENTITY(1, 1) PRIMARY KEY)
    INSERT INTO @BufTable (Value)
        SELECT Tbl.Col.value('.', 'nvarchar(max)')
        FROM   @xml.nodes('//r') Tbl(Col)
        OPTION (OPTIMIZE FOR (@xml = NULL)) 

    INSERT INTO @result (Value, SortOrder)
        SELECT Value, SortOrder
        FROM @BufTable

    RETURN
END

这应该会让你想要你想要的东西：

WITH DataSource AS
(
    SELECT DS.[ColumnA]
          ,DS.[ColumnB]
          ,A.[SortOrder]
          ,ISNULL(NULLIF(B.[value], ''), A.[Value]) AS [Value]
    FROM @DataSource DS
    CROSS APPLY [dbo].[fn_Analysis_ConvertCsvListToNVarCharTableWithOrder] (REPLACE([ColumnA], ',', '~'), '~') A
    LEFT JOIN
    (
        SELECT [ColumnA]
              ,B.[SortOrder]
              ,B.[value]
        FROM @DataSource DS
        CROSS APPLY [dbo].[fn_Analysis_ConvertCsvListToNVarCharTableWithOrder] (REPLACE([ColumnB], ',', '~'), '~') B
    ) B
        ON DS.[ColumnA] = B.[ColumnA]
        AND A.[SortOrder] = B.[SortOrder]
)
SELECT DISTINCT A.[ColumnA]
               ,A.[ColumnB]
               ,DS.[value]
FROM DataSource A
CROSS APPLY
(
    SELECT STUFF
    (
        (
            SELECT '~' + B.[Value]
            FROM DataSource B
            WHERE A.[ColumnA]  = B.[ColumnA]
            ORDER BY B.[SortOrder]
            FOR XML PATH(''), TYPE
        ).value('.', 'VARCHAR(MAX)')
        ,1
        ,1
        ,''
    )
) DS ([value]);

Answer 2

您可以尝试不创建Function()： -

DECLARE @ColumnA NVARCHAR(MAX);
DECLARE @columnB NVARCHAR(MAX);

SET @ColumnA = '~as~df~gf~er ';
SET @columnB = ' ~qw~~~';

;WITH CTE
     AS (
     SELECT Split.a.value('.', 'NVARCHAR(MAX)') DATA,
            ROW_NUMBER() OVER(ORDER BY @ColumnA) RN
     FROM
     (
         SELECT CAST('<M>'+REPLACE(@ColumnA, '~', '</M><M>')+'</M>' AS XML) AS String
     ) AS A
     CROSS APPLY String.nodes('/M') AS Split(a)),
     CTE1
     AS (
     SELECT Split.a.value('.', 'NVARCHAR(MAX)') DATA1,
            ROW_NUMBER() OVER(ORDER BY @columnB) RN
     FROM
     (
         SELECT CAST('<M>'+REPLACE(@columnB, '~', '</M><M>')+'</M>' AS XML) AS String
     ) AS A
     CROSS APPLY String.nodes('/M') AS Split(a))
     SELECT @ColumnA AS ColumnA,
            @columnB AS columnB,
            [Output of columnb] =
     (
         SELECT '~'+CASE
                        WHEN C1.DATA1 = ''
                        THEN C2.DATA
                        ELSE C1.DATA1
                    END
         FROM CTE1 C1
              INNER JOIN CTE C2 ON C2.RN = C1.RN
                                   AND C1.RN > 1 FOR XML PATH('')
     );

期望输出：

ColumnA                columnB        Output of columnb 
~as~df~gf~er            ~qw~~~          ~qw~df~gf~er

如何替换在sql中相同位置的其他列值的特殊字符后？

2 个答案: