删除@符号之前和之后的文本字符串

Question

Am stuck here and would greatly appreciate any help!

R:£30 AT:63 RT:0 D .ADD £400 @63 WK

SQL Task:

1 - retrieve 400 (find symbol @ and take as many characters going left until reached £ symbol)

2 - retrieve 63 (find @ symbol and get as many characters until found " " or "W"

Answer 1

just use charIndex and substring. The example below is assuming that there can be £ after the @ as well. Basically, splitting the string at @, for the 2nd part, i'm going from @ to ' '. the first part, reserve it, find £, then reverse it back.

declare @col varchar(500)
set @col = 'R:£30 AT:63 RT:0 D .ADD £400 @63 WK'
declare @p1 varchar(500),@p2 varchar(500) --split col into 2 at @


set @p1 = (reverse(substring(@col,1,CHARINDEX('@',@col)-1))) -- i will reverse here 
set @p2 = (substring(@col,CHARINDEX('@',@col)+1,LEN(@col)))


select @p1 p1, @p2 p2
    ,ltrim(rtrim(reverse(substring(@p1,1,CHARINDEX('£',@p1)-1)))) p1Final  -- do the same thing as we did to p1 and reserse it
    --also do a trim left and right to get rid of extra spaces 
    ,ltrim(rtrim(SUBSTRING(@p2,1,charIndex(' ',@p2)))) p2Final --this one should be self explanatory if you get the first one :)

Answer 2

You can also use the patindex function that can look for a pattern.

declare @col varchar(50)
set @col='R:£30 AT:63 RT:0 D .ADD £400 @63 WK'

--400
select substring(@col,patindex('% £% @%',@col)+2,charindex('@',@col)-(patindex('% £% @%',@col)+3))

--63
select substring(@col,charindex('@',@col)+1,charindex(' ',reverse(@col))-1)

Answer 3

Not sure about the efficiency, but to get you started

For 1: I reversed the string and manipulated it and then reversed the result back

declare @s varchar(500) = 'R:£30 AT:63 RT:0 D .ADD £23 £400 @63 WK'
declare @sRev varchar(500) = REVERSE(@s)
declare @stemp varchar(500)

declare @ampIndRev int, @AfterAmpIndRev int
set @ampIndRev = CHARINDEX( '@',@sRev,1)

set @AfterAmpIndRev =  charindex('£',@sRev, @ampIndRev) 

set @stemp = SUBSTRING(@sRev, @ampIndRev + 1, @AfterAmpIndRev-@ampIndRev-1)

set @stemp = REVERSE(Ltrim(@stemp))
select @stemp

For 2 (I assumed that you need to look for W only if there is no space):

declare @s varchar(500) = 'R:£30 AT:63 RT:0 D .ADD £400 @63 WK'
declare @ampInd int, @AfterAmpInd int
set @ampInd = CHARINDEX( '@',@s,1)

set @AfterAmpInd = CHARINDEX(' ',@s,@ampInd)
if @AfterAmpInd = 0
    set @AfterAmpInd = CHARINDEX('W',@s,@ampInd)

select SUBSTRING(@s, @ampInd + 1, @AfterAmpInd-@ampInd-1)