Question: I have an XML file with an XSLT stylesheet. Internet Explorer opens and renders the XML file as expected. However, File | Print or File | Print Preview does not show any content. What am I missing?

Thanks.

Answer: 
If you have a simple query like

SELECT \* FROM bookings WHERE user\_id = ORDER BY user\_id ASC;

if you don't check user id, it can close your query, then start a new (harmful one) and discard the rest. To achieve this, generally, you would enter something like

1; DELETE FROM bookings; --

initial ; closes the good query, the bad query comes next, then it is closed with ; and -- makes sure that anything that would come next in the good query is commented out. You then end up with

SELECT \* FROM bookings WHERE user\_id = 1; DELETE FROM bookings; -- ORDER BY user\_id ASC;
Plenty of excellent papers on the theory of SQL injection here:

[sql injection filetype:pdf](http://www.google.co.uk/search?hl=en&rls=com.microsoft%3Aen-gb%3AIE-SearchBox&as_q=sql+injection&as_epq=&as_oq=&as_eq=&num=10&lr=&as_filetype=pdf&ft=i&as_sitesearch=&as_qdr=all&as_rights=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=off)

Should be easy enough to hunt one down that is specific to your language/DB combination.