- STR (nExpression [, nLength, nDecimalPlaces []]) returns the string of the specified expression 
-- nLength, the length of the returned string; NDecimalPlaces, return a string of decimal digits 
Select 
SPACE (u.D epth * 6) + the u.c. ontent as comments, 
U.T hread + LTRIM (STR (u.D epth, 100, 0)) the as sorting 
The from UserComments as u 
The order by u.T hread + LTRIM (STR (u.D epth, 100, 0)) 

The STR () function in mysql as if no, which function should be used instead of