How to generate spaces between letters in Sql Server 2005 (Set Based) - sql-server-2005

Question

Input
Column
ab2e
mnop
a2t1y
output
Id Col1 Col2 Col3 Col4 Col5 Col6
1 a b e
2 m n o p
3 a t y
The numbers indicates the number of spaces
Since in the first input, there is 2 after b, so the letter e will appear after 2 spaces from b.
In the second input since there is no space, the the letters will appear after each other
Thanks

Answer 1

If you've already got a way of distributing a 'normal' string's contents between the columns and only need a solution for expanding strings like ab2e into strings like ab[space][space]e, then here's a possible solution:
DECLARE #InputString varchar(100), #pos int, #result varchar(100);
SET #InputString = 'a2t1y';
SET #result = #InputString;
SET #pos = PATINDEX('%[0-9]%', #result);
WHILE #pos <> 0 BEGIN
SET #result = STUFF(#result, #pos, 1, SPACE(SUBSTRING(#result, #pos, 1)));
SET #pos = PATINDEX('%[0-9]%', #result);
END
SELECT #result;
The output:
---------------------
a t y
It would probably be a nice idea to implement it as a function:
CREATE FUNCTION ExpandString (#String varchar(100))
RETURNS varchar(100)
AS BEGIN
DECLARE #pos int, #result varchar(100);
SET #result = #String;
SET #pos = PATINDEX('%[0-9]%', #result);
WHILE #pos <> 0 BEGIN
SET #result = STUFF(#result, #pos, 1, SPACE(SUBSTRING(#result, #pos, 1)));
SET #pos = PATINDEX('%[0-9]%', #result);
END
RETURN #result;
END
so you could call it on a column like this:
SELECT …, dbo.ExpandString(t.SomeColumn), …
It should be noted, though, that this solution only supports single-digit 'macros', i.e. a12b would be converted to a[1 space][2 spaces]b with this function, which is not necessarily what you'd expect. So, if you need it to recognise integers as sequences of numeric characters between non-numerics, here's an alternative solution:
CREATE FUNCTION ExpandString (#String varchar(100))
RETURNS varchar(100)
AS BEGIN
DECLARE #pos int, #lastpos int, #len int, #isnum bit,
#sub varchar(100), #result varchar(100);
SET #result = '';
SET #pos = 1;
SET #len = LEN(#String);
SET #isnum = ISNUMERIC(SUBSTRING(#String, #pos, 1));
WHILE #pos <= #len BEGIN
SET #lastpos = #pos;
WHILE #pos <= #len AND ISNUMERIC(SUBSTRING(#String, #pos, 1)) = #isnum
SET #pos = #pos + 1;
SET #sub = SUBSTRING(#String, #lastpos, #pos - #lastpos);
SET #result = #result + CASE #isnum WHEN 1 THEN SPACE(#sub) ELSE #sub END;
SET #isnum = #isnum ^ 1;
END;
RETURN #result;
END
Both versions recognise numbers both at the beginning and at the end of the input string.