None besides functions from the standard C library which are always available.

Returns TRUE if every character in text creates some sort of white space, FALSE otherwise. Besides the blank character this also includes tab, vertical tab, line feed, carriage return and form feed characters.

Besides these, you benefit from logging queries either within your script or by the database itself, if it supports. Obviously, the logging is unable to prevent any harmful attempt, but it can be helpful to trace back which application has been circumvented. The log is not useful by itself, but through the information it contains. The more detail is generally better.