I recommend the answer posted by Martin.
But you seem to be concerned about your queries getting too complex:
To create localized table for every table is making design and querying complex...
So you might be thinking, that instead of writing simple queries like this:
SELECT price, name, description FROM Products WHERE price < 100
...you would need to start writing queries like that:
SELECT
p.price, pt.name, pt.description
FROM
Products p JOIN ProductTranslations pt
ON (p.id = pt.id AND pt.lang = "en")
WHERE
price < 100
Not a very pretty perspective.
But instead of doing it manually you should develop your own database access class, that pre-parses the SQL that contains your special localization markup and converts it to the actual SQL you will need to send to the database.
Using that system might look something like this:
db.setLocale("en");
db.query("SELECT p.price, _(p.name), _(p.description)
FROM _(Products p) WHERE price < 100");
And I'm sure you can do even better that that.
The key is to have your tables and fields named in uniform way.