sql-server SQL SERVER中的TRANSLATE函数

vxbzzdmp 于 2022-10-31 发布在 SQL Server

关注(0)|答案(6)|浏览(270)

我读到在SQL Server 2017下DB2下有一个相当于标准函数TRANSLATE的函数，但是在更早的版本下怎么办呢？
对于功能定义：here

sql-server

来源：https://stackoverflow.com/questions/48042049/translate-function-in-sql-server

6条答案

按热度按时间

cigdeys31#

编辑日期：

我感觉自己很笨- MatBailie正确地指出了我原来的解决方案是不正确的。实际上，我一直认为TRANSLATE('abc', 'abc', 'bcd')应该返回ddd，但在测试SQL Server 2017的TRANSLATE后，我发现'bcd'将是正确的答案。通过查看此帖子的历史记录，您可以看到我原来的（不正确的版本）。以下是使用ngrams8k的更新解决方案：

DECLARE
  @string varchar(8000)  = 'abc',
  @fromChar varchar(100) = 'abc', -- note: no mutation
  @toChar varchar(100)   = 'bcd';

SELECT newString = 
(
  SELECT CASE WHEN x>z THEN '' WHEN x>0 THEN s ELSE t END+''
  FROM dbo.ngrams8k(@string,1) ng
  CROSS APPLY (VALUES (charindex(ng.token,@fromChar),len(@toChar),ng.token)) x(x,z,t)
  CROSS APPLY (VALUES (ng.position, substring(@toChar,x.x,1))) xx(p,s)
  ORDER BY xx.p
  FOR XML PATH(''), TYPE
).value('(text())[1]', 'varchar(8000)');

返回值〉bcd

赞(0）回复(0）举报 2022-10-31

x759pob22#

我建议我翻译功能：

CREATE FUNCTION [dbo].[F_Translate]
(
       @String   varchar(8000), 
       @FromChar varchar(200), 
       @ToChar   varchar(200)
)
RETURNS varchar(8000)
AS
BEGIN
        DECLARE @result as varchar(8000) = NULL
        DECLARE @currentChar as char(1) = NULL
        DECLARE @CurrentIndexFounded as int = 0
        DECLARE @CurrentIndexString as int = 0

        IF(@FromChar IS NULL OR @ToChar IS NULL)
        BEGIN
            return cast('Parameters @FromChar and @ToChar must contains 1 caracter minimum' as int);
        END
        ELSE IF(DATALENGTH(@FromChar) <> DATALENGTH(@ToChar) OR DATALENGTH(@FromChar) = 0)
        BEGIN
            return cast('Parameters @FromChar and @ToChar must contain the same number of characters (at least 1 character)' as int);
        END

       IF(@String IS NOT NULL) 
       BEGIN
            SET  @result = '';
            WHILE(@CurrentIndexString < DATALENGTH(@String))
            BEGIN 
                    SET @CurrentIndexString = @CurrentIndexString + 1;
                    SET @currentChar = SUBSTRING(@String, @CurrentIndexString, 1);
                    SET @CurrentIndexFounded  = CHARINDEX(@currentChar COLLATE Latin1_General_CS_AS, @FromChar COLLATE Latin1_General_CS_AS);
                    IF(@CurrentIndexFounded > 0)
                    BEGIN
                            SET @result = CONCAT(@result, SUBSTRING(@ToChar, @CurrentIndexFounded, 1)) ;
                    END
                    ELSE
                    BEGIN
                            SET @result = CONCAT(@result, @currentChar);
                    END
             END
       END
       return @result
END

赞(0）回复(0）举报 2022-10-31

gkn4icbw3#

比WHILE循环更好的是--至少在我看来是这样-a用一个函数 Package 的古怪的更新：
您可以在表中维护替换值。您可以添加一些分组键（例如，用于语言选择或主题焦点），并将其作为附加参数传递给函数：

CREATE TABLE ReplaceValues (FindChar NVARCHAR(100) NOT NULL
                           ,ReplWith NVARCHAR(100) NOT NULL
                           ,SortOrder INT NOT NULL);
INSERT INTO ReplaceValues VALUES('a','x',1)         --all "a" will be "x"
                               ,('test','yeah!',2)  --"test" will be "yeah"
                               ,('hello','ciao',3)  --"hello" will be "ciao"
                               ,('xxx','magic',4);  --this is magic (see below)
GO

--您不能内联使用古怪的更新，但可以将其 Package 在标量函数中：

CREATE FUNCTION dbo.MultiReplace(@ReplaceTarget VARCHAR(MAX))
RETURNS VARCHAR(MAX)
AS
BEGIN
    --Quirky Update: One of the rare situations where this is a good idea 
    SELECT @ReplaceTarget=REPLACE(@ReplaceTarget,rv.FindChar,rv.ReplWith)
    FROM ReplaceValues AS rv
    ORDER BY rv.SortOrder;

    RETURN @ReplaceTarget;
END
GO

--测试数据表

declare @t table(TestString varchar(100))
insert into @t values('This string is without repls')
                    ,('This is a test, hello, one more test')
                    ,('See the cascade replace with aaa, which is converted to xxx, then to magic');

--...and the magic is going in here:

SELECT t.TestString
      ,dbo.MultiReplace(t.TestString) AS Translated
FROM @t AS t
GO

--清理

DROP FUNCTION dbo.MultiReplace;
DROP TABLE ReplaceValues;

结果

This string is without repls
This is x yeah!, ciao, one more yeah!
See the cxscxde replxce with magic, which is converted to magic, then to mxgic

赞(0）回复(0）举报 2022-10-31

9njqaruj4#

我想我也应该把我的想法放进去。这避免了可怕的WHILE循环，而且，也没有使用自引用变量（这可能会变得很糟糕）。
注意，首先使用了Tally表，然后我使用了表值函数（而不是速度较慢的标量函数）来完成这项工作。
注意，我已经设置好了，如果您在右边提供的参数较少，字符将被删除。因此，如果参数@FindChars的值为'AB'，而@ReplaceChars的值为'C'，那么'A'将被替换为' C'，'B'将被替换为''。我注意到，对于TRANSLATE，这将产生错误The second and third arguments of the TRANSLATE built-in function must contain an equal number of characters.
但是，函数的问题在于不能使用THROW或RAISERROR，这意味着在函数内部实际产生错误是不可能的。然而，你可以设置一些东西，以便在两个长度不匹配时返回 NULL，但（不幸的是）错误产生不能在函数内部执行。

CREATE VIEW dbo.Tally WITH SCHEMABINDING
AS 

    WITH C1 AS (SELECT 1 AS I UNION ALL SELECT 1),
         C2 AS (SELECT 1 AS I FROM C1 AS L CROSS JOIN C1 AS R),
         C3 AS (SELECT 1 AS I FROM C2 AS L CROSS JOIN C2 AS R),
         C4 AS (SELECT 1 AS I FROM C3 AS L CROSS JOIN C3 AS R),
         C5 AS (SELECT 1 AS I FROM C4 AS L CROSS JOIN C4 AS R),
         C6 AS (SELECT 1 AS I FROM C5 AS L CROSS JOIN C5 AS R),
         RN AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS N FROM C6)
    SELECT TOP (1000000) N
    FROM RN
    ORDER BY N;
GO

CREATE FUNCTION dbo.OwnTranslate (@String varchar(8000),@FindChars varchar(8000), @ReplaceChars varchar(8000))
RETURNS TABLE
AS RETURN (

    WITH ToBeReplaced AS (
    SELECT @String AS String,
        FC.N,
        SUBSTRING(@FindChars, FC.N,1) AS FC,
        ISNULL(SUBSTRING(@ReplaceChars, RC.N,1),'') AS RC
    FROM (SELECT TOP (LEN(@FindChars)) N FROM Tally) FC
        OUTER APPLY (SELECT TOP (LEN(@ReplaceChars)) T.N FROM Tally T WHERE T.N = FC.N AND T.N <= LEN(@ReplaceChars)) RC),
    Replacing AS (
        SELECT N, REPLACE(String, FC, RC) AS ReplacedString
        FROM ToBeReplaced
        WHERE N = 1
        UNION ALL
        SELECT R.N + 1, REPLACE(ReplacedString, TBR.FC, TBR.RC) AS ReplacedString
        FROM ToBeReplaced TBR
            JOIN Replacing R ON TBR.N = R.N + 1)
    SELECT TOP 1 ReplacedString
    FROM Replacing
    ORDER BY N DESC);
GO

WITH VTE AS (
    SELECT *
    FROM (VALUES ('This is a string to be Translated.')) V(S))
SELECT VTE.S, OT.ReplacedString
FROM VTE
     CROSS APPLY dbo.OwnTranslate (VTE.S, 'Ts ', 'qz_') OT;

GO
--Clean up
DROP FUNCTION dbo.OwnTranslate;
DROP VIEW Tally;

有什么问题，请尽管问。

赞(0）回复(0）举报 2022-10-31

yjghlzjz5#

改编自@Shnugo的答案。这更接近你想要的。你只需要确保你有一个dbo.numbers表 （它们真的很有用）。
http://dbfiddle.uk/?rdbms=sqlserver_2016&fiddle=627828307504174dcf3f61313ba384a8

CREATE FUNCTION dbo.MultiReplace(@ReplaceTarget NVARCHAR(MAX), @from_chars NVARCHAR(MAX), @to_chars NVARCHAR(MAX))
RETURNS NVARCHAR(MAX)
AS
BEGIN
    --Quirky Update: One of the rare situations where this is a good idea 
    SELECT @ReplaceTarget=REPLACE(@ReplaceTarget,SUBSTRING(@from_chars, id+1, 1), SUBSTRING(@to_chars, id+1, 1))
    FROM numbers
    WHERE id < LEN(@from_chars) AND id < LEN(@to_chars)
    ORDER BY id;

    RETURN @ReplaceTarget;
END

和一个稍微过顶的方式来满足你的要求，TRANSLATE('abc', 'abc', 'bcd') => 'bcd')。

CREATE FUNCTION dbo.Translate(@ReplaceTarget NVARCHAR(MAX), @from_chars NVARCHAR(MAX), @to_chars NVARCHAR(MAX))
RETURNS NVARCHAR(MAX)
AS
BEGIN

  DECLARE
    @steps INT = LEN('_' + @from_chars + '_') - 2
  ;

  WITH
    dictionary(id, string_from, string_interim, string_to) AS
  (
    SELECT
      id, string_from, N'<' + string_from + N'>', string_to
    FROM
    (
      SELECT
        id,
        ROW_NUMBER() OVER (PARTITION BY string_from ORDER BY id)  AS occurence,
        string_from,
        string_to
      FROM
        numbers
      CROSS APPLY
      (
        SELECT
          CAST(SUBSTRING(@from_chars, numbers.id, 1) AS NVARCHAR(5))  AS string_from,
          CAST(SUBSTRING(@to_chars,   numbers.id, 1) AS NVARCHAR(5))  AS string_to
      )
        chars
      WHERE
            numbers.id >  0
        AND numbers.id <= @steps
    )
      sorted_dictionary
    WHERE
      occurence = 1
  )
  ,
    mapping_sequence(id, string_from, string_to) AS
  (
              SELECT 1,               N'<',            N'<<>'                        WHERE @from_chars LIKE N'%<%'
    UNION ALL SELECT 2,               N'>',            N'<>>'                        WHERE @from_chars LIKE N'%>%'
    UNION ALL SELECT 3,               N'<<<>>',        N'<<>'                        WHERE @from_chars LIKE N'%<%' AND @from_chars LIKE N'%>%'

    UNION ALL SELECT 3 + id,          string_from,    string_interim FROM dictionary WHERE string_from NOT IN (N'<', N'>')
    UNION ALL SELECT 3 + @steps + id, string_interim, string_to      FROM dictionary
  )
  SELECT
    @ReplaceTarget = REPLACE(@ReplaceTarget, string_from, string_to)
  FROM
    mapping_sequence
  ORDER BY
    id
  ;

  RETURN @ReplaceTarget;

END

http://dbfiddle.uk/?rdbms=sqlserver_2017&fiddle=9dbe7214ac4b5bb00060686cfaa879c2
对上述内容进行可能的小优化（尽可能减少REPLACE调用的数量）...

CREATE FUNCTION dbo.Translate(
  @ReplaceTarget NVARCHAR(MAX),
  @from_chars    NVARCHAR(MAX),
  @to_chars      NVARCHAR(MAX)
)
RETURNS NVARCHAR(MAX)
AS
BEGIN

  DECLARE
    @steps INT = LEN('_' + @from_chars + '_') - 2
  ;

  WITH
    dictionary AS
  (
    SELECT
      id, string_from, string_to
    FROM
    (
      SELECT
        ROW_NUMBER() OVER (    ORDER BY string_from            )  AS id,
        ROW_NUMBER() OVER (PARTITION BY string_from ORDER BY id)  AS occurence,
        string_from,
        string_to
      FROM
        numbers
      CROSS APPLY
      (
        SELECT
          CAST(SUBSTRING(@from_chars, numbers.id, 1) AS NVARCHAR(5))  AS string_from,
          CAST(SUBSTRING(@to_chars,   numbers.id, 1) AS NVARCHAR(5))  AS string_to
      )
        chars
      WHERE
            numbers.id >  0
        AND numbers.id <= @steps
    )
      sorted_dictionary
    WHERE
      occurence = 1
  ),
    two_stage AS
  (
    SELECT
      map.*
    FROM
      dictionary   dict
    CROSS APPLY
    (
      SELECT COUNT(*) FROM dictionary WHERE dictionary.id > dict.id AND dictionary.string_from = dict.string_to
    )
      remap(hits)
    CROSS APPLY
    (
      SELECT id,                     dict.string_from,               dict.string_to          WHERE remap.hits = 0 AND dict.string_from NOT IN (N'<', N'>')
      UNION ALL
      SELECT id,                     dict.string_from,        N'<' + dict.string_from + N'>' WHERE remap.hits > 0 AND dict.string_from NOT IN (N'<', N'>')
      UNION ALL
      SELECT id + @steps,     N'<' + dict.string_from + N'>',        dict.string_to          WHERE remap.hits > 0 AND dict.string_from NOT IN (N'<', N'>')
      UNION ALL
      SELECT id + @steps * 2, N'<' + dict.string_from + N'>',        dict.string_to          WHERE                    dict.string_from     IN (N'<', N'>')
    )
      map
  )
  ,
    mapping_sequence(id, string_from, string_to) AS
  (
              SELECT 1,               N'<',          N'<<>'                   WHERE @from_chars LIKE N'%<%'
    UNION ALL SELECT 2,               N'>',          N'<>>'                   WHERE @from_chars LIKE N'%>%'
    UNION ALL SELECT 3,               N'<<<>>',      N'<<>'                   WHERE @from_chars LIKE N'%<%' AND @from_chars LIKE N'%>%'

    UNION ALL SELECT 3 + id,          string_from,   string_to FROM two_stage
  )
  SELECT
    @ReplaceTarget = REPLACE(@ReplaceTarget, string_from, string_to)
  FROM
    mapping_sequence
  ORDER BY
    id
  ;

  RETURN @ReplaceTarget;

END

http://dbfiddle.uk/?rdbms=sqlserver_2017&fiddle=8af6ae050dc8d425521ae911b70a7968
或者......
http://dbfiddle.uk/?rdbms=sqlserver_2017&fiddle=1451aa88780463b1e7cfe15dd0071194
或者......
http://dbfiddle.uk/?rdbms=sqlserver_2017&fiddle=3079d4dd4289e8696072f6ee37be76ae

赞(0）回复(0）举报 2022-10-31

u2nhd7ah6#

在SQL 2016中，需要删除/替换数值和字符（如单引号和双引号）时，我有一个实用函数，它将translate（）作为一个没有CTE递归的iTVF。在开发过程中，我发现了代理对--虽然在我的用例中不太可能，但在以下示例中得到了解释。

CREATE OR ALTER FUNCTION util.__string_ReturnOnlyAlpha (@input NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
SELECT --(xml).value , remove entities from 
    (SELECT [value] FROM (  
        SELECT TOP(LEN(@input))
            n.[i] , SUBSTRING(@input,n.[i],1) [value] 
        FROM ( SELECT ROW_NUMBER() OVER(ORDER BY (SELECT '.')) [i] FROM 
                STRING_SPLIT(REPLICATE(CAST('.' AS VARCHAR(MAX)),LEN(@input) - 1),'.') 
                ) n([i])
        ORDER BY n.[i]  
        ) ss WHERE ss.[Value] IN (' ') OR ss.[value] LIKE '%[A-Za-z]%'
        FOR XML PATH(''),type 
    ).value('.','nvarchar(max)') [TextValue]
)

GO
GO

/* Translate pt 1/3 : */
CREATE OR ALTER FUNCTION util.__string_AsCharacterRows(@input NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
        SELECT TOP(LEN(@input COLLATE Latin1_General_100_CI_AS_KS_WS_SC))
            n.[i] , CAST(SUBSTRING(@input COLLATE Latin1_General_100_CI_AS_KS_WS_SC,n.[i],1) AS NVARCHAR(2)) [value] 
        FROM ( SELECT ROW_NUMBER() OVER(ORDER BY (SELECT '.')) [i] FROM 
                STRING_SPLIT(REPLICATE(CAST('.' AS VARCHAR(MAX)),LEN(@input) - 1),'.') 
                ) n([i])
        ORDER BY n.[i]  
)

GO
GO

/* Translate pt 2/3 : */
CREATE OR ALTER FUNCTION util.__string__TranslateMap(@inputString NVARCHAR(MAX),@characters NVARCHAR(MAX),@translations NVARCHAR(MAX))
RETURNS TABLE
AS
RETURN
(
    SELECT TOP(LEN(@inputString COLLATE Latin1_General_100_CI_AS_KS_WS_SC))
    s.[i],
    ISNULL(ct.t,s.[value]) [value]
    FROM
    util.__string_AsCharacterRows(@inputString) s
    LEFT HASH JOIN (SELECT 
        c.i,
        c.[value] c,
        t.[value] t
        FROM util.__string_AsCharacterRows(@characters) c
        INNER MERGE JOIN util.__string_AsCharacterRows(@translations) t ON t.i = c.i 
    ) ct ON ct.c = s.[value]
    ORDER BY
    s.[i]
)

GO
GO

/* Translate pt 3/3 : */
CREATE OR ALTER FUNCTION util.__string__Translate(@inputString NVARCHAR(MAX),@characters NVARCHAR(MAX),@translations NVARCHAR(MAX))
RETURNS TABLE
AS
RETURN -- if you have a CLR method for string_agg replacement, use that here. 
(   SELECT
     (SELECT [value] FROM 
        util.__string__TranslateMap(@inputString,@characters,@translations)
       FOR XML PATH(''),type 
    ).value('.','nvarchar(max)') [TextValue]
    --but if you have CLR and can add new methods, maybe use a CLR translate function
)

GO
GO

/*example*/
SELECT 
input.string,        --  in: '😃' & 👍. 
translated.TextValue -- out: "😎" & ✌!
FROM
(VALUES(N'''😃'' & 👍. ')
,(REPLICATE(N'''😃'' & 👍. ',9000))) input(string) --can handle characters over 9000!
CROSS APPLY util.__string__Translate(input.string,N'''😃👍.',N'"😎✌!') translated

这使用了3个iTVF，它们是 Package 器，并重用了前面的一个，但如果需要，您可能可以将其作为子查询写出。内存使用未优化，如果需要，您可能需要等待2017或CLR。

赞(0）回复(0）举报 2022-10-31

我来回答

sql-server SQL SERVER中的TRANSLATE函数

6条答案

相关问题

热门标签

最新问答