select hierarchical item using function - sql

Question

I tried to generate Html from table. And to achieve that, I used function.
TABLE:
LayoutId LayoutDetailsId ParentId DetailSyntax DetailValue
--------------- --------------- --------------- --------------- ---------------
2 15 0 table htmlchild
2 16 15 tbody htmlchild
2 17 16 tr htmlchild
2 18 17 th No.
2 19 17 th Name
2 20 17 th Address
2 21 16 tr htmlchild
2 22 21 td 1
2 23 21 td Asha
2 24 21 td Flamboyan Street
2 25 16 tr htmlchild
2 26 25 td 2
2 27 25 td Jack
2 28 25 td Manggo Street
note that htmlchild in DetailValue is like "HasChild"
FUNCTION:
CREATE FUNCTION FnHtmlGenerator(#layoutId BIGINT, #parentId BIGINT = 0, #prevTopLevelHtml VARCHAR(MAX) = '')
RETURNS VARCHAR(MAX)
AS
BEGIN
DECLARE #currentHtml VARCHAR(MAX);
DECLARE #parentTable TABLE
(
layoutDetailsId BIGINT,
parentId BIGINT,
syntax VARCHAR(50),
val VARCHAR(50)
);
INSERT INTO #parentTable
SELECT
ld.LayoutDetailsId,
ld.ParentId,
ld.DetailSyntax,
ld.DetailValue
FROM Alert.LayoutDetails ld
WHERE ld.ParentId = #parentId
AND ld.LayoutId = #layoutId;
SELECT
#currentHtml = '<' + pt.syntax + '>{0}</' + pt.syntax + '>',
#parentId = pt.layoutDetailsId
FROM #parentTable pt;
SELECT
#prevTopLevelHtml =
CASE CHARINDEX('{0}', #prevTopLevelHtml)
WHEN 0 THEN #currentHtml
ELSE STUFF(#prevTopLevelHtml, CHARINDEX('{0}', #prevTopLevelHtml), 3, #currentHtml)
END;
SELECT
#prevTopLevelHtml =
CASE
(SELECT COUNT(0)
FROM Alert.LayoutDetails ld
WHERE ld.ParentId = #parentId)
WHEN 0 THEN #prevTopLevelHtml
ELSE FnHtmlGenerator(#layoutId, #parentId, #prevTopLevelHtml)
END;
RETURN #prevTopLevelHtml;
END
RESULT:
html
---------------------------------------------------
<table><tbody><tr><td>{0}</td></tr></tbody></table>
The problem is. My function only trace 1 path. the first tr and first td even th is not traced. How to make it trace all path ?

Answer 1

Because when you call
SELECT
#currentHtml = '<' + pt.syntax + '>{0}</' + pt.syntax + '>',
#parentId = pt.layoutDetailsId
FROM #parentTable pt;
... that returns the last row in the table, and assigns that to the variables, so the path is 2/15/16/25/28
You may want to look at the recursive abilities of common table expressions (eg: http://msdn.microsoft.com/en-us/library/ms186243(v=sql.105).aspx) and/or the Hierarchical data type if your database platform supports it (SQL Server 2008+,)