| Subject: | wish: a "strict" mode to force bind variable usage. |
As expressed here:
http://www.perlmonks.org/index.pl?node_id=815974
SQL::Interp is an excellent tool to help build SQL. It can be especially
pleasant to use from DBIx::Simple. Combining the two, you can do this:
$result = $db->iquery("SELECT * FROM foo WHERE a = ",\$b)
It's easy to read, and $b will automatically be translated into a bind
variable. My concern is that on a number of occasions I have seen well
meaning programmers do this instead:
$result = $db->iquery("SELECT * FROM foo WHERE a = ",$b)
The difference is the backslash before the $b. The rub is that the code
produces the same result either way, but the second format has possibly
introduced an opportunity for a SQL injection attack. What suggestions
do you have for how SQL::Interp might detect such cases, so that it can
warn or die? Here are some brainstorms I've thought of, possibly
activated only when a "strict mode" is enabled.
- Scalars are no longer allowed at all. Instead, you would use something
like: "sql('SELECT * from foo WHERE a = '),\$b"
- Assume any two strings in a row is a mistake...you could always
concatenate them instead.
- Parse the SQL sufficiently to understand where bind variables *should*
be and then make sure they are used there.
Each option has its drawbacks, but does one stand out to you as being
better? What other ideas can you think of to address this?