"In order to...", "To..." or "For..."

"For passing" and "for finding" are not correct. "In order to" and "To" are correct, but I favour "To" because it is more concise:

To pass the exams, you have to study a lot.

To find the object in the database, users have to run a SQL query.

A more natural way of saying this is:

You have to study a lot to pass the exams.

Users have to run a SQL query to find the object in the database.

According to BBC World Service, in order to "sounds a bit more formal and explicit" than to.

'For to' is used by Irish (and some Scottish people) in place of 'for the purpose of' or 'in order to'. Using your example: 'I studied, for to pass the exam'. Instead of: 'I studied in order to pass the exam'. I have never heard anyone begin a sentence with 'for to' in this way though, it is usually used as a joining phrase to explicitly explain why something was necessary.

I would actually also say that that is the purpose of saying 'in order to' rather than just 'to'. Someone above has said 'in order to' serves no function as 'to' serves just as well. I disagree. In some contexts it underlines the fact a certain action was necessary for the desired outcome.

I.e. 'I studied to pass the exam' vs. 'I studied in order to pass the exam'. In the second example the onus is on the fact that studying was not just something you did because you wanted to pass an exam, it was something you did because it was essential to you achieving your goal of passing the exam. Language is subtle.

"For to" is a construction right out of nursery rhymes and old songs! I'm going to Louisiana, For to see my Sal (Polly Wolly Doodle)

Simple Simon went a-fishing, for to catch a whale

It's old-fashioned, but it has a flavor of other languages (para, from Spanish, for example) and views on how one approaches doing something. Not a must do, or a to do, but a for doing.