Sorting VARCHAR column which contains integers - sql

Question

I have this table:
IF OBJECT_ID('tempdb..#Test') IS NOT NULL
DROP TABLE #Test;
CREATE TABLE #Test (Col VARCHAR(100));
INSERT INTO #Test
VALUES ('1'), ('2'), ('10'), ('A'), ('B'), ('C1'), ('1D'), ('10HH')
SELECT * FROM #Test
I want to sort by numeric value first and then alphabetically.
Outcome of sort I want to is:
1
1D
2
10
10HH
A
B
C1
Assume structure of entries is one of those (with no dash of course)
number
number-string
string-number
string
if there is an entry like string-number-string, assume it is string-number

Answer 1

It's not pretty, but it works.
SELECT T.Col
FROM #Test T
CROSS APPLY (VALUES(PATINDEX('%[^0-9]%',T.Col)))PI(I)
CROSS APPLY (VALUES(TRY_CONVERT(int,NULLIF(ISNULL(LEFT(T.Col,NULLIF(PI.I,0)-1),LEN(T.Col)),''))))TC(L)
ORDER BY CASE WHEN TC.L IS NULL THEN 1 ELSE 0 END,
TC.L,
T.Col;
Honestly, I would suggest that if you want to order your data like a numerical value you actually store the numerical value in a numerical column; clearly the above should be a numerical prefix value, and then the string suffix. If you then want to then have the values you have, the use a (PERSISTED) computed column. Like this:
CREATE TABLE #Test (Prefix int NULL,
Suffix varchar(100) NULL,
Col AS CONCAT(Prefix, Suffix) PERSISTED);
INSERT INTO #Test (Prefix, Suffix)
VALUES (1,NULL), (2,NULL), (10,NULL), (NULL,'A'), (NULL,'B'), (NULL,'C1'), (1,'D'), (10,'HH');
SELECT Col
FROM #Test
ORDER BY CASE WHEN Prefix IS NULL THEN 1 ELSE 0 END,
Prefix,
Suffix;

Answer 2

This awful and unintuitive solution, that would be unnecessary if you stored the two pieces of data separately, brought to you by bad idea designs™:
;WITH cte AS
(
SELECT Col, rest = SUBSTRING(Col, pos, 100),
possible_int = TRY_CONVERT(bigint, CASE WHEN pos <> 1 THEN
LEFT(Col, COALESCE(NULLIF(pos,0),100)-1) END)
FROM (SELECT Col, pos = PATINDEX('%[^0-9]%', Col) FROM #Test) AS src
)
SELECT Col FROM cte
ORDER BY CASE
WHEN possible_int IS NULL THEN 2 ELSE 1 END,
possible_int,
rest;
Result:
Col
1
1D
2
10
10HH
A
B
C1
Example db<>fiddle