russellolson (10/16/2012)
The example code above showed this statement:SELECT RowData + ''
FROM Groups b
WHERE a.rn = b.rn FOR XML PATH('')
Why is the + '' required? When I remove this then I get an result that looks like XML instead of a concatenated string.
If I Cast Rowdata to a varchar then the + '' is not required.
Thanks for the explanation.
The XML tag is generated because if you remove the + '' you are now formatting a named column into the string, hence the XML tag. With the + '', it is an unnamed column so hence no XML tag.
CASTing rowdata has the same effect - producing an unnamed column.
I tend to use the former because it is fewer keystrokes. I suppose I should be more scientific and base my choice on performance, but I confess I've never tried it.
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St