Question

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。我想从每一行中分离每个逗号分隔的字符串，并逐行将它们插入到临时表中，而不重复。我想为此表创建一个存储过程，其中包含表名和列作为该存储过程的参数。

这是表格

0 0 0 0 0 1
0 0 0 0 1 0
0 0 0 1 0 0
0 0 1 0 0 0
0 1 0 0 0 0
1 0 0 0 0 0

以下是

的数据

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]

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

Answer 1

使用Parse进行交叉应用应该可以解决问题

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 - 没有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

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

需要的UDF

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)

想要一个逗号分隔字符串的存储过程，该字符串在表中是一列（有20000行）

1 个答案: