Changing money to numeric breaks this dynamic SQL approach - sql-server

Question

This article has a "query to html" approach which seems clean and elegant. But if I change the money data type to numeric, I get an error:
converting data type varchar to numeric
My version:
CREATE OR ALTER PROC dbo.usp_ConvertQuery2HTMLTable
AS
BEGIN
DECLARE #columnslist NVARCHAR (1000) = ''
DECLARE #restOfQuery NVARCHAR (2000) = ''
DECLARE #DynTSQL NVARCHAR (3000)
DECLARE #FROMPOS INT
SET NOCOUNT ON
CREATE TABLE #Products
(
Product [varchar](50) NULL,
UnitPrice [numeric](20, 6) NULL
)
INSERT INTO #Products
SELECT 'Nougat Creme', 14.00
UNION
SELECT 'Gorgonzola', 12.00
UNION
SELECT 'Ale', 14.00
UNION
SELECT 'Chocolate', 10.00
UNION
SELECT 'Lager', 12.00
UNION
SELECT 'Bread', 9.00
DECLARE #SQLQuery NVARCHAR(3000) = 'SELECT Product, cast(UnitPrice as varchar) as UnitPrice FROM #Products';
SELECT #columnslist += 'ISNULL (' + NAME + ',' + '''' + ' ' + '''' + ')' + ','
FROM sys.dm_exec_describe_first_result_set(#SQLQuery, NULL, 0)
SET #columnslist = left (#columnslist, Len (#columnslist) - 1)
SET #FROMPOS = CHARINDEX ('FROM', #SQLQuery, 1)
SET #restOfQuery = SUBSTRING(#SQLQuery, #FROMPOS, LEN(#SQLQuery) - #FROMPOS + 1)
SET #columnslist = Replace (#columnslist, '),', ') as TD,')
SET #columnslist += ' as TD'
SET #DynTSQL = CONCAT (
'SELECT (SELECT '
, #columnslist
,' '
, #restOfQuery
,' FOR XML RAW (''TR''), ELEMENTS, TYPE) AS ''TBODY'''
,' FOR XML PATH (''''), ROOT (''TABLE'')'
)
EXEC (#DynTSQL)
--PRINT #DynTSQL;
SET NOCOUNT OFF
END
GO

Answer 1

I think this procedure is overly complicated, and uses dynamic SQL where it is simply not warranted.
We can do this much easier, by taking a query, adding FOR XML RAW, ELEMENTS, TYPE to it, and passing it to the procedure, then using XQuery to generate the table.
CREATE OR ALTER PROC dbo.usp_ConvertQuery2HTMLTable
#xml xml
AS
SELECT #xml.query('
<TABLE><TBODY>
{ for $row in /row
return element TR {
for $col in $row/*
return element TD {
data($col)
}
}
}
</TBODY></TABLE>
');
You execute it like this:
DECLARE #xml xml = (
SELECT Product, UnitPrice FROM #Products
FOR XML RAW, ELEMENTS, TYPE
);
EXEC usp_ConvertQuery2HTMLTable #xml = #xml;
You can even add column headers. And it's probably even better as a Table Valued function.
CREATE OR ALTER FUNCTION dbo.ConvertQuery2HTMLTable
( #xml xml )
RETURNS TABLE
AS RETURN
SELECT HtmlTable = #xml.query('
<TABLE><TBODY>
<TR>
{
for $colName in /row[1]/*
return element TD { element b {local-name($colName)} }
}
</TR>
{
for $row in /row
return element TR {
for $col in $row/*
return element TD {
data($col)
}
}
}
</TBODY></TABLE>
');
You then execute very simply like this (note the double parenthesis)
SELECT *
FROM ConvertQuery2HTMLTable((
SELECT Product, UnitPrice FROM #Products
FOR XML RAW, ELEMENTS, TYPE
));
db<>fiddle

Answer 2

Instead of cast(UnitPrice as varchar), you should use FORMAT (docs here) to convert the numeric to a currency string. It is even flexible enough to let you pick the appropriate locale formatting as well.
FORMAT(UnitPrice, 'C', 'en-us') AS 'UnitPrice'

Answer 3

First, I had pasted a version of query where I had tried another fix ( that didn't work) - the CAST(). I did fix it by chaging ISNULL() to COALESCE()
DECLARE #columnslist NVARCHAR (1000) = ''
DECLARE #restOfQuery NVARCHAR (2000) = ''
DECLARE #DynTSQL NVARCHAR (3000)
DECLARE #FROMPOS INT
IF OBJECT_ID('tempdb..#Products') IS NOT NULL
DROP TABLE #Products
CREATE TABLE #Products
(
Product [varchar](50) NULL,
UnitPrice [numeric](20, 6) NULL
)
INSERT INTO #Products
SELECT 'Nougat Creme', 14.00
UNION
SELECT 'Gorgonzola', 12.00
UNION
SELECT 'Ale', 14.00
UNION
SELECT 'Chocolate', 10.00
UNION
SELECT 'Lager', 12.00
UNION
SELECT 'Bread', 9.00
DECLARE #SQLQuery NVARCHAR(3000) = 'SELECT Product, UnitPrice FROM #Products';
SELECT #columnslist += 'COALESCE(' + NAME + ',' + '''' + ' ' + '''' + ')' + ','
FROM sys.dm_exec_describe_first_result_set(#SQLQuery, NULL, 0)
SET #columnslist = left (#columnslist, Len (#columnslist) - 1)
SET #FROMPOS = CHARINDEX ('FROM', #SQLQuery, 1)
SET #restOfQuery = SUBSTRING(#SQLQuery, #FROMPOS, LEN(#SQLQuery) - #FROMPOS + 1)
SET #columnslist = Replace (#columnslist, '),', ') as TD,')
SET #columnslist += ' as TD'
SET #DynTSQL = CONCAT (
'SELECT (SELECT '
, #columnslist
,' '
, #restOfQuery
,' FOR XML RAW (''TR''), ELEMENTS, TYPE) AS ''TBODY'''
,' FOR XML PATH (''''), ROOT (''TABLE'')'
)
PRINT (#DynTSQL)
EXEC (#DynTSQL)