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With T-SQL, I'm trying to find the easiest way to reverse numbers in string. so for string like Test123Hello have Test321Hello.
[Before] [After]
Test123Hello Test321Hello
Tt143 Hello Tt341 Hello
12Hll 21Hll
Tt123H3451end Tt321H1543end
you can use this function
CREATE FUNCTION [dbo].[fn_ReverseDigit_MA]
(
#Str_IN nVARCHAR(max)
)
RETURNS NVARCHAR(max)
AS
BEGIN
DECLARE #lenstr AS INT =LEN(#Str_IN)
DECLARE #lastdigend AS INT=0
while (#lastdigend<#lenstr)
BEGIN
DECLARE #strPart1 AS NVARCHAR(MAX)=LEFT(#Str_IN,#lastdigend)
declare #lenstrPart1 AS INT=LEN(#strPart1)
DECLARE #strPart2 AS NVARCHAR(MAX)=RIGHT(#Str_IN,#lenstr-#lastdigend)
declare #digidx as int=patindex(N'%[0-9]%' ,#strPart2)+#lenstrPart1
IF(#digidx=#lenstrPart1)
BEGIN
BREAK;
END
DECLARE #strStartdig AS NVARCHAR(MAX) = RIGHT(#Str_IN,#lenstr-#digidx+1)
declare #NDidx as int=patindex(N'%[^0-9]%' ,#strStartdig)+#digidx-1
IF(#NDidx<=#digidx)
BEGIN
SET #NDidx=#lenstr+1
END
DECLARE #strRet AS NVARCHAR(MAX)=LEFT(#Str_IN,#digidx-1) +REVERSE(SUBSTRING(#Str_IN,#digidx,#NDidx-#digidx)) +RIGHT(#Str_IN,#lenstr-#NDidx+1)
SET #Str_IN=#strRet
SET #lastdigend=#NDidx-1
END
return #Str_IN
END
Just make use of PATINDEX for searching, append to the result string part by part:
CREATE FUNCTION [dbo].[fn_ReverseDigits]
(
#Value nvarchar(max)
)
RETURNS NVARCHAR(max)
AS
BEGIN
IF #Value IS NULL
RETURN NULL
DECLARE
#TextIndex int = PATINDEX('%[^0-9]%', #Value),
#NumIndex int = PATINDEX('%[0-9]%', #Value),
#ResultValue nvarchar(max) = ''
WHILE LEN(#ResultValue) < LEN(#Value)
BEGIN
-- Set the index to end of the string if the index is 0
SELECT #TextIndex = CASE WHEN #TextIndex = 0 THEN LEN(#Value) + 1 ELSE LEN(#ResultValue) + #TextIndex END
SELECT #NumIndex = CASE WHEN #NumIndex = 0 THEN LEN(#Value) + 1 ELSE LEN(#ResultValue) + #NumIndex END
IF #NumIndex < #TextIndex
SELECT #ResultValue = #ResultValue + REVERSE(SUBSTRING(#Value, #NumIndex, #TextIndex -#NumIndex))
ELSE
SELECT #ResultValue = #ResultValue + (SUBSTRING(#Value, #TextIndex, #NumIndex - #TextIndex))
-- Update index variables
SELECT
#TextIndex = PATINDEX('%[^0-9]%', SUBSTRING(#Value, LEN(#ResultValue) + 1, LEN(#Value) - LEN(#ResultValue))),
#NumIndex = PATINDEX('%[0-9]%', SUBSTRING(#Value, LEN(#ResultValue) + 1, LEN(#Value) - LEN(#ResultValue)))
END
RETURN #ResultValue
END
Test SQL
declare #Values table (Value varchar(20))
INSERT #Values VALUES
('Test123Hello'),
('Tt143 Hello'),
('12Hll'),
('Tt123H3451end'),
(''),
(NULL)
SELECT Value, dbo.fn_ReverseDigits(Value) ReversedValue FROM #Values
Result
Value ReversedValue
-------------------- --------------------
Test123Hello Test321Hello
Tt143 Hello Tt341 Hello
12Hll 21Hll
Tt123H3451end Tt321H1543end
NULL NULL
hope this help:
declare #s nvarchar(128) ='Test321Hello'
declare #numStart as int, #numEnd as int
select #numStart =patindex('%[0-9]%',#s)
select #numEnd=len(#s)-patindex('%[0-9]%',REVERSE(#s))
select
SUBSTRING(#s,0,#numstart)+
reverse(SUBSTRING(#s,#numstart,#numend-#numstart+2))+
SUBSTRING(#s,#numend+2,len(#s)-#numend)
Use this function it will handle multiple occurrence of numbers too
create FUNCTION [dbo].[GetReverseNumberFromString] (#String VARCHAR(2000))
RETURNS VARCHAR(1000)
AS
BEGIN
DECLARE #Count INT
DECLARE #IntNumbers VARCHAR(1000)
declare #returnstring varchar(max)=#String;
SET #Count = 0
SET #IntNumbers = ''
WHILE #Count <= LEN(#String)
BEGIN
IF SUBSTRING(#String, #Count, 1) >= '0'
AND SUBSTRING(#String, #Count, 1) <= '9'
BEGIN
SET #IntNumbers = #IntNumbers + SUBSTRING(#String, #Count, 1)
END
IF (
SUBSTRING(#String, #Count + 1, 1) < '0'
OR SUBSTRING(#String, #Count + 1, 1) > '9'
)
AND SUBSTRING(#String, #Count, 1) >= '0'
AND SUBSTRING(#String, #Count, 1) <= '9'
BEGIN
SET #IntNumbers = #IntNumbers + ','
END
SET #Count = #Count + 1
END
declare #RevStrings table (itemz varchar(50))
INSERT INTO #RevStrings(itemz)
select items from dbo.Split(#IntNumbers,',')
select #returnstring = Replace(#returnstring, itemz,REVERSE(itemz))from #RevStrings
RETURN #returnstring
END
your sample string
select [dbo].[GetReverseNumberFromString]('Tt123H3451end')
result
Tt321H1543end
UPDATE :
if you do not have Split function then first create it
i have included it below
create FUNCTION Split
(
#Input NVARCHAR(MAX),
#Character CHAR(1)
)
RETURNS #Output TABLE (
Items NVARCHAR(1000)
)
AS
BEGIN
DECLARE #StartIndex INT, #EndIndex INT
SET #StartIndex = 1
IF SUBSTRING(#Input, LEN(#Input) - 1, LEN(#Input)) <> #Character
BEGIN
SET #Input = #Input + #Character
END
WHILE CHARINDEX(#Character, #Input) > 0
BEGIN
SET #EndIndex = CHARINDEX(#Character, #Input)
INSERT INTO #Output(Items)
SELECT SUBSTRING(#Input, #StartIndex, #EndIndex - 1)
SET #Input = SUBSTRING(#Input, #EndIndex + 1, LEN(#Input))
END
RETURN
END
GO
This is a set based approach:
;WITH Tally (n) AS
(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) a(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) b(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) c(n)
), UnpivotCTE AS (
SELECT id, x.c, n, y.isNumber,
n - ROW_NUMBER() OVER (PARTITION BY id, y.isNumber
ORDER BY n) AS grp
FROM mytable
CROSS JOIN Tally
CROSS APPLY (SELECT SUBSTRING(col, n, 1)) AS x(c)
CROSS APPLY (SELECT ISNUMERIC(x.c)) AS y(isNumber)
WHERE n <= LEN(col)
), ToConcatCTE AS (
SELECT id, c, n, isNumber,
grp + MIN(n) OVER (PARTITION BY id, isNumber, grp) AS grpAsc
FROM UnpivotCTE
)
SELECT id, col,
REPLACE(
(SELECT c AS [text()]
FROM ToConcatCTE AS t
WHERE t.id = m.id
ORDER BY id,
grpAsc,
CASE WHEN isNumber = 0 THEN n END,
CASE WHEN isNumber = 1 THEN n END DESC
FOR XML PATH('')), ' ',' ') AS col2
FROM mytable AS m
A tally table is used in order to 'unpivot' all characters of the string. Then ROW_NUMBER is used in order to identify islands of numeric and non-numeric characters. Finally, FOR XML PATH is used to reconstruct the initial string with numerical islands reversed: ORDER BY is used to sort islands of numeric characters in reversed order.
Fiddle Demo here
This would do the specific string you are asking for:
select
substring('Test123Hello',1,4)
+
reverse(substring('Test123Hello',5,3))
+
substring('Test123Hello',8,5)
Judging by the rest of the values it looks like you would need to make templates for any of the alphanumeric patterns you are getting. For example you would apply the above to any values that had the shape:
select * from [B&A] where [before] like '[a-z][a-z][a-z][a-z][0-9][0-9][0-9]
[a-z][a-z][a-z][a-z][a-z]'
In other words, if you put the values (before and after) into a table [B&A] and called the columns 'before' and 'after' then ran this:
select
substring(before,1,4)
+
reverse(substring(before,5,3))
+
substring(before,8,5) as [after]
from [B&A] where [before] like '[a-z][a-z][a-z][a-z][0-9][0-9][0-9][a-z]
[a-z][a-z][a-z][a-z]'
Then it would give you 'Test321Hello'.
However the other 3 rows would not be affected unless you created a similar
'[0-9][a-z]' type template for each alphanumeric shape and applied this to the [B&A] table. You would have to select the results into a temp table or another table.
By applying each template in turn you'd get most of it then you'd have to see how many rows were unaffected and check what the alphanumeric shape is and make more templates. Eventually you have a set of code which, if you ran it would capture all possible combinations.
You could just sit down and design a code in this way which captured all possible combinations of [a-z] and [0-9]. A lot depends on the maximum number of characters you are dealing with.
I've trying to create a UDF in SQL to return the longest word in a string. I've created the following but I cant get it to work properly. Any suggestions?
CREATE FUNCTION [dbo].[ufn_Longestword] (#input varchar(255))
RETURNS varchar(100)
AS
BEGIN
declare #pos int
declare #pos2 int
declare #wordpos int
declare #longestword varchar(100)
declare #Letter1 varchar (1)
declare #Letter2 varchar (1)
declare #twords table (
words varchar(100))
SET #pos = 1
WHILE #pos <= len(#input)
BEGIN
SET #Letter1 = substring(#input, #pos, 1)
IF #Letter1 = ' '
BEGIN
SET #pos2 = #pos
WHILE #pos2 <= len(#input)
BEGIN
SET #Letter2 = substring(#input, #pos2, 1)
if #letter2 = ' '
BEGIN
insert into #twords
select SUBSTRING(#input, #pos,#pos2 - #pos)
END
SET #pos2 = #pos2 + 1
END
END
SET #pos = #pos + 1
END
SET #longestword = (select top 1 words from #twords
ORDER BY len(words)desc)
delete from #twords
RETURN #longestword
END
I#m trying to get the different between the 2 spaces and insert that word into a temp table but it doesnt work.
Instead you can use this.
DECLARE #str VARCHAR(5000)='aaaa bbbbb cccccccc'
SELECT TOP 1 Split.a.value('.', 'VARCHAR(100)') as longest_Word
FROM (SELECT Cast ('<M>' + Replace(#str, ' ', '</M><M>') + '</M>' AS XML) AS Data) AS A
CROSS APPLY Data.nodes ('/M') AS Split(a)
ORDER BY Len(Split.a.value('.', 'VARCHAR(100)')) DESC
Result : cccccccc
i found this as solution :
click Here
CREATE FUNCTION FN_ex06(#str varchar(8000) )
RETURNS #T TABLE
( position int IDENTITY PRIMARY KEY,
value varchar(8000) ,
length smallint null
)
AS
BEGIN
DECLARE #i int
SET #i = -1
WHILE (LEN(#str) > 0)
BEGIN
SET #i = CHARINDEX(' ' , #str) /* here i used space as delimiter*/
IF (#i = 0) AND (LEN(#str) > 0)
BEGIN
INSERT INTO #T (value, length) VALUES (#str, LEN(#str))
BREAK
END
IF (#i > 1)
BEGIN
INSERT INTO #T (value, length) VALUES (LEFT(#str, #i - 1),
LEN(LEFT(#str, #i - 1)))
SET #str = RIGHT(#str, (LEN(#str) - #i))
END
ELSE
SET #str = RIGHT(#str, (LEN(#str) - #i))
END
RETURN
END
to run this function you treat it as table because return is a table
select max(value) from FN_ex06('karim pentester')
result is : pentester
of course you select all other columns in return table
My table has one column that contain strings like: ” HRM_APPLICATION_DELAY_IN”
I want to perform bellow operations on each row on this column
convert to lower case
remove underscore “_”
change case (convert to upper case) of the character after the underscore like: ” hrm_Application_Delay_In”
Need help for conversion. Thanks for advance
Here is a function to achieve it:
create function f_test
(
#a varchar(max)
)
returns varchar(max)
as
begin
set #a = lower(#a)
while #a LIKE '%\_%' ESCAPE '\'
begin
select #a = stuff(#a, v, 2, upper(substring(#a, v+1,1)))
from (select charindex('_', #a) v) a
end
return #a
end
Example:
select dbo.f_test( HRM_APPLICATION_DELAY_IN')
Result:
hrmApplicationDelayIn
To update your table here is an example how to write the syntax with the function:
UPDATE <yourtable>
SET <yourcolumn> = dbo.f_test(col)
WHERE <yourcolumn> LIKE '%\_%' ESCAPE '\'
For a variable this is overkill, but I'm using this to demonstrate a pattern
declare #str varchar(100) = 'HRM_APPLICATION_DELAY_IN';
;with c(one,last,rest) as (
select cast(lower(left(#str,1)) as varchar(max)),
left(#str,1), stuff(lower(#str),1,1,'')
union all
select one+case when last='_'
then upper(left(rest,1))
else left(rest,1) end,
left(rest,1), stuff(rest,1,1,'')
from c
where rest > ''
)
select max(one)
from c;
That can be extended to a column in a table
-- Sample table
declare #tbl table (
id int identity not null primary key clustered,
str varchar(100)
);
insert #tbl values
('HRM_APPLICATION_DELAY_IN'),
('HRM_APPLICATION_DELAY_OUT'),
('_HRM_APPLICATION_DELAY_OUT'),
(''),
(null),
('abc<de_fg>hi');
-- the query
;with c(id,one,last,rest) as (
select id,cast(lower(left(str,1)) as varchar(max)),
left(str,1), stuff(lower(str),1,1,'')
from #tbl
union all
select id,one+case when last='_'
then upper(left(rest,1))
else left(rest,1) end,
left(rest,1), stuff(rest,1,1,'')
from c
where rest > ''
)
select id,max(one)
from c
group by id
option (maxrecursion 0);
-- result
ID COLUMN_1
1 hrm_Application_Delay_In
2 hrm_Application_Delay_Out
3 _Hrm_Application_Delay_Out
4
5 (null)
6 abc<de_Fg>hi
select
replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace(replace(replace(replace(lower('HRM_APPLICATION_DELAY_IN'),'_a','A'),'_b','B'),'_c','C'),'_d','D'),'_e','E'),'_f','F'),
'_g','G'),'_h','H'),'_i','I'),'_j','J'),'_k','K'),'_l','L'),
'_m','M'),'_n','N'),'_o','O'),'_p','P'),'_q','Q'),'_r','R'),
'_s','S'),'_t','T'),'_u','U'),'_v','V'),'_w','W'),'_x','X'),
'_y','Y'),'_z','Z'),'_','')
Bellow two steps can solve problem,as example i use sys.table.user can use any one
declare #Ret varchar(8000), #RetVal varchar(8000), #i int, #count int = 1;
declare #c varchar(10), #Text varchar(8000), #PrevCase varchar, #ModPrefix varchar(10);
DECLARE #FileDataTable TABLE(TableName varchar(200))
INSERT INTO #FileDataTable
select name FROM sys.tables where object_name(object_id) not like 'sys%' order by name
SET #ModPrefix = 'Pur'
DECLARE crsTablesTruncIns CURSOR
FOR select TableName FROM #FileDataTable
OPEN crsTablesTruncIns
FETCH NEXT FROM crsTablesTruncIns INTO #Text
WHILE ##FETCH_STATUS = 0
BEGIN
SET #RetVal = '';
select #i=1, #Ret = '';
while (#i <= len(#Text))
begin
SET #c = substring(#Text,#i,1)
--SET #Ret = #Ret + case when #Reset=1 then UPPER(#c) else LOWER(#c)
IF(#PrevCase = '_' OR #i = 1)
SET #Ret = UPPER(#c)
ELSE
SET #Ret = LOWER(#c)
--#Reset = case when #c like '[a-zA-Z]' then 0 else 1 end,
if(#c like '[a-zA-Z]')
SET #RetVal = #RetVal + #Ret
if(#c = '_')
SET #PrevCase = '_'
else
SET #PrevCase = ''
SET #i = #i +1
end
SET #RetVal = #ModPrefix + #RetVal
print cast(#count as varchar) + ' ' + #RetVal
SET #count = #count + 1
EXEC sp_RENAME #Text , #RetVal
SET #RetVal = ''
FETCH NEXT FROM crsTablesTruncIns INTO #Text
END
CLOSE crsTablesTruncIns
DEALLOCATE crsTablesTruncIns
I'd like to show you my nice and simple solution. It uses Tally function to split the string by pattern, in our case by underscope. For understanding Tally functions, read this article.
So, this is how my tally function looks like:
CREATE FUNCTION [dbo].[tvf_xt_tally_split](
#String NVARCHAR(max)
,#Delim CHAR(1))
RETURNS TABLE
as
return
(
WITH Tally AS (SELECT top (select isnull(LEN(#String),100)) n = ROW_NUMBER() OVER(ORDER BY [name]) from master.dbo.syscolumns)
(
SELECT LTRIM(RTRIM(SUBSTRING(#Delim + #String + #Delim,N+1,CHARINDEX(#Delim,#Delim + #String + #Delim,N+1)-N-1))) Value, N as Ix
FROM Tally
WHERE N < LEN(#Delim + #String + #Delim)
AND SUBSTRING(#Delim + #String + #Delim,N,1) = #Delim
)
)
This function returns a table, where each row represents part of string between #Delim (in our case between underscopes). Rest of the work is simple, just cobination of LEFT, RIGHT, LEN, UPPER and LOWER functions.
declare #string varchar(max)
set #string = ' HRM_APPLICATION_DELAY_IN'
-- convert to lower case
set #string = LOWER(#string)
declare #output varchar(max)
-- build string
select #output = coalesce(#output + '_','') +
UPPER(left(Value,1)) + RIGHT(Value, LEN(Value) - 1)
from dbo.tvf_xt_tally_split(#string, '_')
-- lower first char
select left(lower(#output),1) + RIGHT(#output, LEN(#output) - 1)
i was searching script to extract number from text in sql server and i found this
CREATE FUNCTION [dbo].[GetNumbersFromText](#String VARCHAR(2000))
RETURNS #Number TABLE (Number INT)
AS
BEGIN
DECLARE #Count INT
DECLARE #IntNumbers VARCHAR(1000)
SET #Count = 0
SET #IntNumbers = ''
WHILE #Count <= LEN(#String)
BEGIN
--Find a numeric charactor
IF SUBSTRING(#String,#Count,1) >= '0' AND SUBSTRING(#String,#Count,1) <= '9'
BEGIN
SET #IntNumbers = #IntNumbers + SUBSTRING(#String,#Count,1)
END
--If the next charactor is not a numeric one, the current number ends, so add a separator
IF (SUBSTRING(#String,#Count+1,1) < '0'OR SUBSTRING(#String,#Count+1,1) > '9') AND SUBSTRING(#String,#Count,1) >= '0' AND SUBSTRING(#String,#Count,1) <= '9'
BEGIN
SET #IntNumbers = #IntNumbers + ','
END
SET #Count = #Count + 1
END
---Split string to give a table with the numbers in the text
INSERT INTO #Number
SELECT DISTINCT items FROM dbo.Split(#IntNumbers, ',')
return
END
and call it like
SELECT Number FROM Dbo.[GetNumbersFromText]('Give me 120 this week and 50 next week')
it works fine but i need more short code. can i use patindex to extract number from text.
please anyone share small & good logic to do so. thanks
This is a bit shorter. Turned it into Inline Table Function that uses a recursive CTE to find the numbers.
create function [dbo].[GetNumbersFromText](#String varchar(2000))
returns table as return
(
with C as
(
select cast(substring(S.Value, S1.Pos, S2.L) as int) as Number,
stuff(s.Value, 1, S1.Pos + S2.L, '') as Value
from (select #String+' ') as S(Value)
cross apply (select patindex('%[0-9]%', S.Value)) as S1(Pos)
cross apply (select patindex('%[^0-9]%', stuff(S.Value, 1, S1.Pos, ''))) as S2(L)
union all
select cast(substring(S.Value, S1.Pos, S2.L) as int),
stuff(S.Value, 1, S1.Pos + S2.L, '')
from C as S
cross apply (select patindex('%[0-9]%', S.Value)) as S1(Pos)
cross apply (select patindex('%[^0-9]%', stuff(S.Value, 1, S1.Pos, ''))) as S2(L)
where patindex('%[0-9]%', S.Value) > 0
)
select Number
from C
)
If you expect to have more than 100 numbers in the string you need to call it with option (maxrecursion 0).
declare #S varchar(max)
set #S = 'Give me 120 this week and 50 next week'
select number from GetNumbersFromText(#S) option (maxrecursion 0)
#Vikram's basic idea is not bad, but their query would return all the numbers as a single item. The following function returns a table containing separate numbers as found in the source string:
CREATE FUNCTION dbo.GetNumbersFromText (#String varchar(2000))
RETURNS TABLE
AS
RETURN (
WITH NumbersSplit AS (
SELECT
C = SUBSTRING(#String, number, 1),
i = number,
g = number - ROW_NUMBER() OVER (ORDER BY number)
FROM master..spt_values
WHERE type = 'P'
AND SUBSTRING(#String, number, 1) BETWEEN '0' AND '9'
),
NumbersAssembled AS (
SELECT
number = CAST(
(SELECT C + '' FROM NumbersSplit WHERE g = g.g ORDER BY i FOR XML PATH (''))
AS varchar(2000)
)
FROM NumbersSplit g
GROUP BY g
)
SELECT * FROM NumbersAssembled
)
Note: this solution would work in SQL Server 2005 or later.
try the following logic:
declare #thestring varchar(50)
set #thestring = 'Give me 120 this week and 50 next week'
declare #final varchar(50)
set #final = ''
select #final = #final + x.thenum
from
(
select substring(#thestring, number, 1) as thenum, number
from master..spt_values
where substring(#thestring, number, 1) like '[0-9]' and type='P'
) x
order by x.number
print #final
-- Try This Code...
-- Its OK!!!
CREATE FUNCTION [dbo].[udf_ExtractNumberFromString]
(
#pInputString VARCHAR(MAX)
)
RETURNS VARCHAR(MAX)
AS
BEGIN
DECLARE #OutputString varchar(MAX)=''
DECLARE #string varchar(MAX)
DECLARE #start INT
DECLARE #end INT
DECLARE #len INT
SET #string=#pInputString
--SET #string = 'the22478ddffafghrty12345TestAddressdd5aa789324-#345'
SET #string = replace(#string, ' ' , '')
WHILE PATINDEX('%[0-9]%',#string) <> 0
BEGIN
SET #len = len(#string)
-- PRINT #len
set #start = PATINDEX('%[0-9]%',#string)
-- PRINT #start
SET #end= PATINDEX('%[^0-9]%',SUBSTRING(#string,#start,#len-#start))
-- PRINT #end
IF #end=0
BEGIN
SET #end=#len-#start
SET #OutputString=SUBSTRING(#string,#start,#end+1)+'-'+#OutputString
BREAK
END
ELSE
BEGIN
SET #OutputString=SUBSTRING(#string,#start,#end-1)+'-'+#OutputString
SET #string=SUBSTRING(#string,#end+#start-1,#len-#end)
END
--PRINT #string
--PRINT #Output
--PRINT '---------------------'
END
IF LEN(#OutputString)>0
SET #OutputString=LEFT(#OutputString,LEN(#OutputString)-1)
--PRINT #OutputString
RETURN #OutputString
END
Here is an appropriate and working solution for this query
http://www.ittutorials.in/source/sql/sql-function-to-extract-only-numbers-from-string.aspx
I wanted to know if in SQL Server there is an equivalent to the Oracle INSTR function?
I know that there is CHARINDEX and PATINDEX, but with the Oracle version I can also specify the Nth appearance of the character(s) I am looking for.
Oracle INSTR:
instr( string1, string2 [, start_position [, **nth_appearance** ] ] )
The CHARINDEX almost gets me there, but I wanted to have it start at the nth_appearance of the character in the string.
You were spot on that nth_appearance does not exist in SQL Server.
Shamelessly copying a function (Equivalent of Oracle's INSTR with 4 parameters in SQL Server) created for your problem (please note that #Occurs is not used the same way as in Oracle - you can't specify "3rd appearance", but "occurs 3 times"):
CREATE FUNCTION udf_Instr
(#str1 varchar(8000), #str2 varchar(1000), #start int, #Occurs int)
RETURNS int
AS
BEGIN
DECLARE #Found int, #LastPosition int
SET #Found = 0
SET #LastPosition = #start - 1
WHILE (#Found < #Occurs)
BEGIN
IF (CHARINDEX(#str1, #str2, #LastPosition + 1) = 0)
BREAK
ELSE
BEGIN
SET #LastPosition = CHARINDEX(#str1, #str2, #LastPosition + 1)
SET #Found = #Found + 1
END
END
RETURN #LastPosition
END
GO
SELECT dbo.udf_Instr('x','axbxcxdx',1,4)
GO
DROP FUNCTION udf_Instr
GO
Here is a version of Oracle's INSTR function which also works with a negative position for a reverse lookup as per Oracle's Doc here :- https://docs.oracle.com/cd/B28359_01/olap.111/b28126/dml_functions_1103.htm#OLADM564
CREATE FUNCTION dbo.INSTR(#str NVARCHAR(MAX), #substr NVARCHAR(MAX), #position INT = 1, #occurance INT = 1)
RETURNS INT
AS
BEGIN
DECLARE #loc INT = #position;
IF #loc < 0
BEGIN
SET #str = REVERSE(#str);
SET #substr = REVERSE(#substr);
SET #loc = #loc * -1;
END
IF #loc > 0
BEGIN
SET #loc = #loc - 1;
END
WHILE (#occurance > 0 AND CHARINDEX(#substr, #str, #loc + 1) > 0)
BEGIN
SET #loc = CHARINDEX(#substr, #str, #loc + 1);
SET #occurance = #occurance - 1;
END
IF #occurance > 0
BEGIN
SET #loc = 0;
END
IF #position < 0
BEGIN
SET #loc = LEN(#str) - #loc;
END
RETURN #loc
END
Change #str1 varchar(8000), #str2 varchar(1000) to #str1 varchar(1000), #str2 varchar(8000)
or
change CHARINDEX(#str1, #str2, #LastPosition + 1) to CHARINDEX(#str2, #str1, #LastPosition + 1)
You can use the following UDF (inline function rather than scalar)
CREATE FUNCTION dbo.INSTR
(
#str VARCHAR(8000),
#Substr VARCHAR(1000),
#start INT ,
#Occurance INT
)
RETURNS TABLE
AS
RETURN
WITH Tally (n) AS
(
SELECT TOP (LEN(#str)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0)) a(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) b(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) c(n)
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) d(n)
)
, Find_N_STR as
(
SELECT
CASE WHEN DENSE_RANK() OVER(PARTITION BY #Substr ORDER BY (CHARINDEX(#Substr ,#STR ,N))) = #Occurance
THEN MAX(N-#start +1) OVER (PARTITION BY CHARINDEX(#Substr ,#STR ,N) )
ELSE 0
END [Loc]
FROM Tally
WHERE CHARINDEX(#Substr ,#STR ,N) > 0
)
SELECT Loc= MAX(Loc)
FROM Find_N_STR
WHERE Loc > 0
How to use:
declare #T table
(
Name_Level_Class_Section varchar(25)
)
insert into #T values
('Jacky_1_B2_23'),
('Johnhy_1_B2_24'),
('Peter_2_A5_3')
select t.Name_Level_Class_Section , l.Loc
from #t t
cross apply dbo.INSTR (t.Name_Level_Class_Section, '_',1,2) l
Try this !!
CREATE FUNCTION dbo.INSTR (#str VARCHAR(8000), #substr VARCHAR(255), #start INT, #occurrence INT)
RETURNS INT
AS
BEGIN
DECLARE #found INT = #occurrence,
#pos INT = #start;
WHILE 1=1
BEGIN
-- Find the next occurrence
SET #pos = CHARINDEX(#substr, #str, #pos);
-- Nothing found
IF #pos IS NULL OR #pos = 0
RETURN #pos;
-- The required occurrence found
IF #found = 1
BREAK;
-- Prepare to find another one occurrence
SET #found = #found - 1;
SET #pos = #pos + 1;
END
RETURN #pos;
END
GO
Usage :
-- Find the second occurrence of letter 'o'
SELECT dbo.INSTR('Moscow', 'o', 1, 2);
-- Result: 5