Question

表格包含Title字段和Tags字段。标签是通过来自文档的潜在Dirichlet分配（LDA）生成的，并且可以是例如标签。＆＃39; 鱼，烤箱，时间＆＃39; 烧烤，啤酒＆＃39;或者＆＃39; <肉>烧烤＆＃39;标签的长度不固定。

给定一组标签，如何找到匹配最大标签数量的记录，无论标签的顺序如何？

所以，如果＆＃39; BBQ，肉＆＃39;得到最好的结果应该是＆＃39; 肉类，烧烤＆＃39;。如果＆＃39; 烧烤，鱼，奶油＆＃39;给出所有三个记录都可以返回（它们都有一个匹配的标记）。

Answer 1

使用this function并创建此

    CREATE FUNCTION dbo.getCountOfMatch ( @mainString VARCHAR(MAX),  @searchString nvarchar(max))
    RETURNS
      INT
    AS
    BEGIN
        DECLARE @returnCount INT

        SELECT 
            @returnCount = COUNT(1)
        FROM 
            splitstring(@mainString) A INNER JOIN 
            splitstring(@searchString) B ON A.Name = B.Name

        RETURN @returnCount
    END

和

    SELECT TOP 1 // What you want
      Title,
      Tags
    FROM
    (
        SELECT
            A.Title,
            A.Tags,
            dbo.getCountOfMatch(A.Tags, @search) CountTags -- The number of matches.
        FROM
            TABLE A
    ) B
    ORDER BY B.CountTags DESC

<强>已更新

DECLARE @searchText NVARCHAR(MAX) = 'BBQ, meat'
DECLARE @query NVARCHAR(MAX) = '
        SELECT
            *
        FROM
            Table
        WHERE '

SELECT
    @query += 
    (
        SELECT
            'Tags like ''%' + A.Name + '%'' AND ' -- Dont forget trim!
        FROM 
            splitstring(@searchText) A
        FOR XML PATH ('')
    )

SELECT @query = LEFT(@query, LEN(@query) - 4) + 'ORDER BY LEN(Tags)' -- For exactly matching: LEN(Tags) = LEN(@searchText)

EXEC sp_executesql  @query

查询看起来像;

    SELECT
        *
    FROM
        Table
    WHERE 
        Tags like '%BBQ%' AND 
        Tags like '%meat%'
    ORDER BY LEN(Tags)

Answer 2

结合两个UDF，您可以返回搜索的命中率（百分比）。

例如

Select [dbo].[udf-Str-Match-Rate]('Dog,House,Custom',',','The dog house is red',' ')

返回0.6666 - 找到3个单词/短语中的2个。

每个人都可以拥有自己的分隔符

仅测试不同的单词以避免夸大结果

我还包括一个soundex（这是可选的）

第一个UDF是独立的，可以单独使用。

CREATE FUNCTION [dbo].[udf-Str-Parse] (@String varchar(max),@delimeter varchar(10))
--Usage: Select * from [dbo].[udf-Str-Parse]('Dog,Cat,House,Car',',')
--       Select * from [dbo].[udf-Str-Parse]('John Cappelletti was here',' ')
--       Select * from [dbo].[udf-Str-Parse]('id26,id46|id658,id967','|')

Returns @ReturnTable Table (Key_PS int IDENTITY(1,1) NOT NULL , Key_Value varchar(max))

As

Begin
   Declare @intPos int,@SubStr varchar(max)
   Set @IntPos = CharIndex(@delimeter, @String)
   Set @String = Replace(@String,@delimeter+@delimeter,@delimeter)
   While @IntPos > 0
      Begin
         Set @SubStr = Substring(@String, 0, @IntPos)
         Insert into @ReturnTable (Key_Value) values (@SubStr)
         Set @String = Replace(@String, @SubStr + @delimeter, '')
         Set @IntPos = CharIndex(@delimeter, @String)
      End
   Insert into @ReturnTable (Key_Value) values (@String)
   Return 
End

第二个UDF需要第一个

CREATE FUNCTION [dbo].[udf-Str-Match-Rate] (@SearchFor varchar(max),@SearchForDelim varchar(5),@SearchIn varchar(max),@SearchInDelim varchar(5))

-- Syntax : Select [dbo].[udf-Str-Match-Rate]('Dog,House,Custom',',','The dog house is red',' ')

Returns money
AS
  BEGIN

    Declare @RetVal money

    ;with cteSearchFor  as (Select Distinct Key_Value from [dbo].[udf-Str-Parse](@SearchFor ,@SearchForDelim))
         ,cteSearchIn as (Select Distinct Key_Value from [dbo].[udf-Str-Parse](@SearchIn,@SearchInDelim))
         ,cteWordCnt as (Select Words=cast(count(*) as money) From cteSearchFor)
    Select @RetVal = isnull(Count(*)/max(Words),0)
      From cteSearchFor S 
      Join cteWordCnt W on 1=1
      Join cteSearchIn C
        on S.Key_Value = C.Key_Value
        or Soundex(S.Key_Value) = Soundex(C.Key_Value)

    Return @RetVal

  END

Answer 3

创建表格标签并使用Coq website

填充

tags
title PK
tag   PK  

select title, count(*) 
from tags 
where tag in ('BBQ', 'fish', 'cream') 
group by title 
having count(*) > 1

SELECT * 
from table 
join dbo.splitstring(table.tags)

TSQL匹配尽可能多的逗号分隔标记

3 个答案: