sql natural sort by strings mixed with numbers in one label - sql

Question

I came with a problem of sorting using ORDER BY. I found a lot of similar questions, but no answer fits my needs. The task is:
I have column [LABEL] which contains strings, and i want to get an order like this:
label
'1'
'2'
'11R'
'11T9'
'11T10'
'RT_5'
'RT_6'
'RT_10'
'RT_10b'
'RT_10dyn'
and so on...
instead of:
'1'
'11R'
'11T10'
'11T9'
'2S'
'RT_10'
'RT_10b'
'RT_10dyn'
'RT_5'
'RT_6'
the label columb might be like any combination of characters.
The problem is to find numbers in names, and if it is possible to sort by those numbers, then by other charaters...

Answer 1

After a few hours here is the solution:
I created a function to change the labels in specific way:
Each NUMBER in the input #in is replaced by the same number
writen in #digits chars WITH leadings zeros.
For example:
#digit = 4, #in = 'aa300bb' return = '_aa0300bb_'.
#digit = 5, #in = 'aa300bb' return = '_aa00300bb_'.
#digit = 3, #in = 'a2c4e5' return = '_a002c004e005_'.
And here is the function:
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[fnMixSort]')
AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[fnMixSort]
GO
CREATE FUNCTION [dbo].[fnMixSort] (
#in NVARCHAR(250),
#digits int
) RETURNS NVARCHAR(1000) AS
BEGIN
DECLARE
#starts int,
#i int, -- position where next NUMBER starts
#j int, -- position where next NUMBER ends
#temp nvarchar(1000)
set #starts = 1
set #in = '_' + #in + '_' -- extended LABEL: protection from EMPTY input
while (1=1)
begin
select #temp = substring(#in, #starts, len(#in))
-- #i #j - start/end position of first number
SELECT #i = COALESCE( PATINDEX('%[0-9]%',#temp ), 0)
SELECT #j = COALESCE( PATINDEX('%[0-9][^0-9]%',#temp ), 0)
if #i = 0 break -- no more NUMBERs in the LABEL
-- now we PUT at posiotion=#i+#start-1 specific numbers of '0'
select #in = STUFF(#in, #i + #starts - 1, 0, REPLICATE('0', #digits-#j+#i-1))
select #starts = #starts + #i + #digits - 1
end
-- -------- return ---------
RETURN #in
END
GO
lets create some table to check the function:
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[aaaa_test]')
AND type in (N'U'))
DROP TABLE [dbo].[aaaa_test]
GO
CREATE TABLE [dbo].[aaaa_test](
Label [varchar](255) NULL
)
INSERT INTO [dbo].[aaaa_test] ([Label])
VALUES ('bb'),('aa12'),(''),('30'),('10rt'),
('12ru'),('1rt'),('9rt'),('aa8'),('aa10'),('aa'),
('12rz'),('12rt'),('9rt5'),('9_rt_10_23'),('9_rt_10_5'),('9rt12'),
('12rz34'),('12rz3'),('12rz35c'),('12rz105b'),('12rt'),('9rt5'),('9rt10'),('9rt12')
select
[label]
,dbo.fnMixSort(Label,5) as [fnMixSort_returns]
from [dbo].[aaaa_test]
order by dbo.fnMixSort(Label,5)
And the result
label fnMixSort_returns
----------------------------------
1rt _00001rt_
9_rt_10_5 _00009_rt_00010_00005_
9_rt_10_23 _00009_rt_00010_00023_
9rt _00009rt_
9rt5 _00009rt00005_
9rt5 _00009rt00005_
9rt10 _00009rt00010_
9rt12 _00009rt00012_
9rt12 _00009rt00012_
10rt _00010rt_
12rt _00012rt_
12rt _00012rt_
12ru _00012ru_
12rz _00012rz_
12rz3 _00012rz00003_
12rz34 _00012rz00034_
12rz35c _00012rz00035c_
12rz105b _00012rz00105b_
30 _00030_
aa _aa_
aa8 _aa00008_
aa10 _aa00010_
aa12 _aa00012_
bb _bb_
it was my first time to post here...
hope it will help someone oneday..

Answer 2

You can substr [LABEL] column into different columns and then order by those columns. As null is sorted first you don't need to do anything extra for values with less character.
How ever you can also follow this thread here.
Here in this solution the logic is :-
If ID is numeric, add 21 '0's in front of the ID value and get the last 20 characters.
If ID is not numeric, add 21 ‘’s at the end of the ID value and get the first 20 characters.
Or this is a better solution for you query Sort Alphanumeric value
Let us see if it helps.

Answer 3

ANOTHER SOLUTION: different exchanged_label:
/** ==========================================================
FUNCTION DESCRIPTION
-------------------------------------------------------------
Function for special sorting - natural-mix sorting.
Order by : number in word are treated as number, not as a
characters only.
So 'a2' is before 'a10' and '9R' is before '10R' ...
-------------------------------------------------------------
Function puts special prefix before each number.
If number has 1 digit -> with prefix is 0A
If number has 2 digits -> with prefix is 0B
... ... ...
If number has 16 digits -> with prefix is 0P
If number has 17 digits -> with prefix is 0PA
If number has 18 digits -> with prefix is 0PB
... ... ...
If number has 32 digits -> with prefix is 0PP
If number has 33 digits -> with prefix is 0PPA
... and so on...
For example:
aa123bb9 -> aa0C123bb0A9
**/
CODE
CREATE FUNCTION [dbo].[fnMixSort] ( #in NVARCHAR(1000) ) RETURNS NVARCHAR(1000) AS
BEGIN
DECLARE
#starts int,
#i int, -- position where next NUMBER starts
#j int, -- position where next NUMBER ends
#temp nvarchar(1000)
set #starts = 1
set #in = '_' + #in + '_' -- extended LABEL: protection from EMPTY input
while (1=1)
begin
select #temp = substring(#in, #starts, len(#in))
SELECT #i = COALESCE( PATINDEX('%[0-9]%',#temp ), 0)
if #i = 0 break -- no more NUMBERs in the LABEL
SELECT #j = COALESCE( PATINDEX('%[0-9][^0-9]%',#temp ), 0)
select #temp = '0' -- numbers->must still be numbers: before letters
while (#j >= #i + 16)
begin
select #j = #j - 16
select #temp = #temp + 'P'
end
select #temp = #temp + CHAR(#j - #i + 65) -- char(65) is 'A'
select #in = STUFF(#in, #i + #starts - 1, 0, #temp)
select #starts = #starts + LEN(#temp) + (LEN(#temp)-2)*16 + #j
end -- while
RETURN #in
END
GO
results:
1rt _0A1rt_
9_rt_10_5 _0A9_rt_0B10_0A5_
9_rt_10_23 _0A9_rt_0B10_0B23_
9rt _0A9rt_
9rt5 _0A9rt0A5_
9rt5 _0A9rt0A5_
9rt10 _0A9rt0B10_
9rt12 _0A9rt0B12_
9rt12 _0A9rt0B12_
10rt _0B10rt_
12rt _0B12rt_
12rt _0B12rt_
12ru _0B12ru_
12rz _0B12rz_
12rz3 _0B12rz0A3_
12rz34 _0B12rz0B34_
12rz105b _0B12rz0C105b_
30 _0B30_
9234567890123456123456789012345rz38c _0PO9234567890123456123456789012345rz0B38c_
12345678901234561234567890123456rz35c _0PP12345678901234561234567890123456rz0B35c_
123456789012345612345678901234561rz36c _0PPA123456789012345612345678901234561rz0B36c_
aa _aa_
aa0A _aa0A0A_
aa0b _aa0A0b_
aa8 _aa0A8_
aa10 _aa0B10_
aa12 _aa0B12_
bb _bb_

Answer 4

Same approach as pi.314 but rewrite for PostgreSQL:
CREATE OR REPLACE FUNCTION fnNumberAwareSort(value varchar, digits integer)
RETURNS varchar
AS '
DECLARE
numbers VARCHAR[];
texts VARCHAR[];
BEGIN
value = CONCAT(''_'', value, ''_'');
SELECT ARRAY(SELECT res[1] FROM regexp_matches(value, ''\d+'', ''g'') AS res) INTO numbers;
texts = regexp_split_to_array(value, ''\d+'');
FOR i IN 1..array_upper(texts,1) LOOP
numbers[i] = lpad(numbers[i], digits, ''0'');
END LOOP;
value = texts[1];
FOR i IN 2..array_upper(texts,1) LOOP
value = value || numbers[i-1] || texts[i];
END LOOP;
RETURN value;
END;
' LANGUAGE plpgsql;