SQL injection

Hi all,

I'm currently trying to build a defence against SQL INJECTION, after
reading some material on it I arrived to few possible solutions and I
would like to know if anyone can comment anything about them or maybe
add a solution of its own:

1. PachyRand: SQL Randomization for the PostgreSQL JDBC Driver - seems
to be the best solution (easiest and most protective) though I didnt
understood entirely if the solution is available for production
enviorments or not, information can be attained at:
http://nsl.cs.columbia.edu/projects/pachyrand/ &
http://mice.cs.columbia.edu/getTechreport.php?techreportID=355&format=pdf&

2. Running for each data which will be used at the db checks with
regular expressions to find out if its valid, this method is quite
complicated to me (dont know regular expressions too much) and it
demands diffrent checks to each data field (with quite big problems at
open text data), at the end im afraid that holes will exist..

3. Running PHP functions like settype($data, 'integer') to be sure that
the data which arrive is at the correct format and to the text run
pg_escape_string($data), I suspect that this method wont block even
close to 100% of the attacks, just like the former option.

Another factor is the overhead to the system, I think that the previous
methods don't create much overhead but if anyone have another idea of
course it will also need to be efficent.

Any new ideas or comments will be received gladly.

Thanks in advance!
Yonatan Ben-Nes