wählen bestimmte Zeichenfolge aus einer Spalte

Question

I-Daten in einer Tabelle, die wie folgt aussieht:

select email_body from email_table 


email_body 
---------- 
Ashely, call me. thanks --- Original message --- From: Ashley To: Lee Subject: Homework Sent: 3/6/2017 2:32:54 AM GMT I have a quick question. 
Mike, I have all the data you need. Jim --- Original message --- From: Mike To: Jim Subject: Not Sure Sent: 3/18/2017 12:02:51 AM GMT Are you available to go over this? 
William, Are you around. thanks --- Original message --- From: Joe To: William Subject: Nothing much Sent: 4/16/2017 4:17:23 PM GMT I need some sleep. 
Joan, call me. Ralph --- Original message --- From: Ralph To: Joan Subject: I need help Sent: 3/30/2017 5:12:50 AM GMT Call Rich. 

Ich möchte nur das Datum und die Uhrzeit in der email_body aufgeführt zurück:

Results: 

Original_message 
---------------- 
3/6/2017 2:32:54 AM 
3/18/2017 12:02:51 AM 
4/16/2017 4:17:23 PM 
3/30/2017 5:12:50 AM 

Answer 1

Sie verwendet wird, könnte so etwas wie

select SUBSTRING (email_body , PATINDEX ('Subject' ,email_body)+1, 18) from email_table 

Answer 2

Da die Datenlänge (zB 1/1/2017 vs 01.237.326 variieren), Sie müssen finden, wo es beginnt (das ist einfach - 6 Zeichen nach dem Sent:) und wo es endet (das wäre 2 Zeichen vor M GMT). Der Rest ist mit substring erledigt.

SELECT SUBSTRING(email_body, CHARINDEX('Sent:', email_body) + 6, 
CHARINDEX('M GMT ',email_body) - 2 - CHARINDEX('Sent:', email_body) - 6) as Original_message 
FROM email_table 

Answer 3

Wenn Sie einen Tabellenwert-Funktion geöffnet sind, die schnell wird und sicher ein oder sogar basieren viele Werte extrahieren auf einem Muster, UND, sind Sie müde von all den erforderlichen String-Manipulationen, sollten die folgende:

Beispiel

Declare @email_table table (id int,email_body varchar(max)) 
Insert Into @email_table values 
(1,'Ashely, call me. thanks --- Original message --- From: Ashley To: Lee Subject: Homework Sent: 3/6/2017 2:32:54 AM GMT I have a quick question.'), 
(2,'Mike, I have all the data you need. Jim --- Original message --- From: Mike To: Jim Subject: Not Sure Sent: 3/18/2017 12:02:51 AM GMT Are you available to go over this?'), 
(3,'William, Are you around. thanks --- Original message --- From: Joe To: William Subject: Nothing much Sent: 4/16/2017 4:17:23 PM GMT I need some sleep.'), 
(4,'Joan, call me. Ralph --- Original message --- From: Ralph To: Joan Subject: I need help which was Sent: 3/30/2017 5:12:50 AM GMT Call Rich.') 

Select A.ID 
     ,Original_message = B.RetVal 
From @email_table A 
Cross Apply [dbo].[udf-Str-Extract](A.email_body,' Sent: ',' GMT ') B 

Returns

ID Original_message 
1 3/6/2017 2:32:54 AM 
2 3/18/2017 12:02:51 AM 
3 4/16/2017 4:17:23 PM 
4 3/30/2017 5:12:50 AM 

Die tatsächliche TVF kehrt

RetSeq RetPos RetLen RetVal 
1  101  19  3/6/2017 2:32:54 AM 
1  115  21  3/18/2017 12:02:51 AM 
1  114  20  4/16/2017 4:17:23 PM 
1  111  20  3/30/2017 5:12:50 AM 

Die UDF, wenn Sie interessieren

CREATE FUNCTION [dbo].[udf-Str-Extract] (@String varchar(max),@Delimiter1 varchar(100),@Delimiter2 varchar(100)) 
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 N1,cte1 N2,cte1 N3,cte1 N4,cte1 N5,cte1 N6) A), 
     cte3(N) As (Select 1 Union All Select t.N+DataLength(@Delimiter1) From cte2 t Where Substring(@String,t.N,DataLength(@Delimiter1)) = @Delimiter1), 
     cte4(N,L) As (Select S.N,IsNull(NullIf(CharIndex(@Delimiter1,@String,s.N),0)-S.N,8000) From cte3 S) 

Select RetSeq = Row_Number() over (Order By N) 
     ,RetPos = N 
     ,RetLen = charindex(@Delimiter2,RetVal)-1 
     ,RetVal = left(RetVal,charindex(@Delimiter2,RetVal)-1) 
From (Select A.N,RetVal = ltrim(rtrim(Substring(@String, A.N, A.L))) From cte4 A) A 
Where charindex(@Delimiter2,RetVal)>1 
) 
/* 
Max Length of String 1MM characters 

Declare @String varchar(max) = 'Dear [[FirstName]] [[LastName]], ...' 
Select * From [dbo].[udf-Str-Extract] (@String,'[[',']]') 
*/