Question

假设我有一个由某些类别代码组织的短语表：

category   phrase
0            "hello bye"
0            "hello no"
1            "hello bye"
1            "yes no"
2            "hello bye"

然后我想要一个表来计算每个部分每个关键字的出现次数：

category   keyword    frequency
0          "hello"        2
0          "no"           1
0          "bye"          1
1          "hello"        1
1          "bye"          1
1          "yes"          1
1          "no"           1
2          "hello"        1
2          "bye"          1

要查找我以前使用此代码的关键字：

DECLARE @xml XML
SET @xml = '<c>' + replace(
    (select DISTINCT ' ' + phrase
    FROM myTable
    FOR XML PATH('')
), ' ', '</c><c>') + '</c>'

但我想不出用这种方法跟踪类别的方法......

Answer 1

拆分功能

CREATE FUNCTION [dbo].[udf_Split]
(
    @RowData nvarchar(2000),
    @SplitOn nvarchar(5)
)  
RETURNS @RtnValue table 
(
    Id int identity(1,1),
    Data nvarchar(100)
) 
AS  
BEGIN 
    Declare @Cnt int
    Set @Cnt = 1

    While (Charindex(@SplitOn,@RowData)>0)
    Begin
        Insert Into @RtnValue (data)
        Select 
            Data = ltrim(rtrim(Substring(@RowData,1,Charindex(@SplitOn,@RowData)-1)))

        Set @RowData = Substring(@RowData,Charindex(@SplitOn,@RowData)+1,len(@RowData))
        Set @Cnt = @Cnt + 1
    End

    Insert Into @RtnValue (data)
    Select Data = ltrim(rtrim(@RowData))

    Return
END

您的数据

DECLARE @TABLE TABLE (category INT,phrase VARCHAR(50))
INSERT INTO @TABLE VALUES
(0,'hello bye'),(0,'hello no'),(1,'hello bye'),
(1,'yes no'),(2,'hello bye')

<强>查询

SELECT   category
       , Data AS keyword
       , COUNT(Data) AS frequency
FROM   @TABLE t  CROSS APPLY 
                 (SELECT * FROM [dbo].[udf_Split](t.phrase, ' '))C
GROUP BY category,Data 
ORDER BY category

结果集

╔══════════╦═════════╦═══════════╗
║ category ║ keyword ║ frequency ║
╠══════════╬═════════╬═══════════╣
║        0 ║ bye     ║         1 ║
║        0 ║ hello   ║         2 ║
║        0 ║ no      ║         1 ║
║        1 ║ bye     ║         1 ║
║        1 ║ hello   ║         1 ║
║        1 ║ no      ║         1 ║
║        1 ║ yes     ║         1 ║
║        2 ║ bye     ║         1 ║
║        2 ║ hello   ║         1 ║
╚══════════╩═════════╩═══════════╝

SqlFiddle Demo

如何计算关键字在表格的每个部分显示的次数？

1 个答案: