想要一个逗号分隔字符串的存储过程，它是表中的一列(有 20000 行) [英] Want a stored procedure for comma seperated string which is of a column (has 20000 rows ) in a table

问题描述

我有一个包含 20000 行的表，以及一个包含逗号分隔字符串的列.我想从每一行拆分每个逗号分隔的字符串，并将它们逐行插入到临时表中，没有任何重复项.我想为此表创建一个存储过程，并将表名和列作为该存储过程的参数.

I have a table with 20000 rows, and a column that has comma-separated strings in it. I want split each of the comma-separated strings from each row and insert them into a temp table row by row without any duplicates. I want to create a stored procedure for this table with has table name and column as parameters to that stored procedure.

这是表

CREATE TABLE [dbo].[Campaign]
(
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [MISC] [nvarchar](4000) NULL,

    PRIMARY KEY CLUSTERED ([ID] ASC)
                WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, 
                      IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON,
                      ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

这是有

insert into Campaign(MISC) 
values ('h101,h202,h506,h707,h112,h566'),
       ('h101,h102,h508,h113,h456,h678'),
       ('h110,h880,h432,h111,h102,h509,h213'),
       ('h456,h609,h432,h456,h678,h101,h807')

我有单个字符串的登录名，但我不知道如何处理给定列中这 20000 行逗号分隔的字符串 - 有什么帮助吗?

I have a the login for single string but I don't know how to deal with these 20000 rows of comma-separated strings in the given column - any help?

推荐答案

Cross Apply 和 Parse 应该可以解决问题

A Cross Apply with a a Parse should do the trick

选项 1 - 使用 UDF

Select A.ID
      ,B.* 
  From Campaign A
  Cross Apply [dbo].[tvf-Str-Parse-8K](A.Misc,',') B

选项 2 - 不使用 UDF

Select A.ID
      ,B.* 
  From Campaign A
  Cross Apply (
                Select RetSeq = Row_Number() over (Order By (Select null))
                      ,RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)')))
                From  (Select x = Cast('<x>' + replace((Select replace(A.Misc,',','§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.')) as A 
                Cross Apply x.nodes('x') AS B(i)
              ) B

两者都返回

ID  RetSeq RetVal
1   1       h101
1   2       h202
1   3       h506
1   4       h707
1   5       h112
1   6       h566
2   1       h101
2   2       h102
2   3       h508
...
4   3       h432
4   4       h456
4   5       h678
4   6       h101
4   7       h807

UDF(如果需要)

CREATE FUNCTION [dbo].[tvf-Str-Parse-8K] (@String varchar(max),@Delimiter varchar(25))
Returns Table 
As
Return (  
    with   cte1(N)   As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
           cte2(N)   As (Select Top (IsNull(DataLength(@String),0)) Row_Number() over (Order By (Select NULL)) From (Select N=1 From cte1 a,cte1 b,cte1 c,cte1 d) A ),
           cte3(N)   As (Select 1 Union All Select t.N+DataLength(@Delimiter) From cte2 t Where Substring(@String,t.N,DataLength(@Delimiter)) = @Delimiter),
           cte4(N,L) As (Select S.N,IsNull(NullIf(CharIndex(@Delimiter,@String,s.N),0)-S.N,8000) From cte3 S)

    Select RetSeq = Row_Number() over (Order By A.N)
          ,RetVal = LTrim(RTrim(Substring(@String, A.N, A.L)))
    From   cte4 A
);
--Orginal Source http://www.sqlservercentral.com/articles/Tally+Table/72993/
--Much faster than str-Parse, but limited to 8K
--Select * from [dbo].[udf-Str-Parse-8K]('Dog,Cat,House,Car',',')
--Select * from [dbo].[udf-Str-Parse-8K]('John||Cappelletti||was||here','||')
--Performance On a 5,000 random sample -8K 77.8ms, -1M 79ms (+1.16), -- 91.66ms (+13.8)

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