Question

我正在尝试查找一部分不同的电子邮件地址（pryr::mem_change()）在包含一段文字的列中，该段落可能包含一个或多个电子邮件地址实例。我的表格包含几行带有段落，我正在尝试识别使用@gmail.com的唯一电子邮件地址。

预先感谢

表A

@gmail.com

Answer 1

在段落中的空格上使用拆分功能，这很简单。

Check The Online Demo Here

@ORM\GeneratedValue(strategy="IDENTITY")

Here is the function from Jeff Moden

declare @table table (p varchar(4000))
insert into @table
values
('this paragrapsh contains one@gmail.com and duplicate one@gmail.com and one.two@gmail.com and one_two_three@gmail.com. How neat is that? Pretty neat eh!?')


select distinct 
    --case statement removed periods from end of email for when it's at the end of a sentence
    case when right(x.Item,1) != 'm' then left(x.Item,len(x.Item) - 1) else x.Item end
from @table t
cross apply dbo.DelimitedSplit8K(p,' ') x
where x.Item like '%@gmail.com%'

使用新提供的数据和DEMO HERE

CREATE FUNCTION [dbo].[DelimitedSplit8K] (@pString VARCHAR(8000), @pDelimiter CHAR(1))
--WARNING!!! DO NOT USE MAX DATA-TYPES HERE!  IT WILL KILL PERFORMANCE!

RETURNS TABLE WITH SCHEMABINDING AS
RETURN

/* "Inline" CTE Driven "Tally Table" produces values from 1 up to 10,000...
enough to cover VARCHAR(8000)*/

  WITH E1(N) AS (
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
                ),                          --10E+1 or 10 rows
       E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
       E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
 cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
                     -- for both a performance gain and prevention of accidental "overruns"
                 SELECT TOP (ISNULL(DATALENGTH(@pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
                ),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
                 SELECT 1 UNION ALL
                 SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(@pString,t.N,1) = @pDelimiter
                ),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
                 SELECT s.N1,
                        ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)
                   FROM cteStart s
                )
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
 SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
        Item       = SUBSTRING(@pString, l.N1, l.L1)
   FROM cteLen l
;

从SQL中的列中选择不同的子字符串出现

1 个答案: