Question

I am planning to replace repeatedly executed Statement objects with PreparedStatement objects to improve performance. I am using arguments like the MySQL function now(), and string variables.

Most of the PreparedStatement queries I have seen contained constant values (like 10, and strings like 'New York') as arguments used for the ? in the queries. How would I go about using functions like now(), and variables as arguments? Is it necessary to use the ?s in the queries instead of actual values? I am quite confounded.

Answer 1

If you have variables use the ‘?’

int temp = 75; PreparedStatement pstmt = con.prepareStatement(     'UPDATE test SET num = ?, due = now() '); pstmt.setInt(1, temp);  pstmt.executeUpdate(): 

Produces an sql statment that looks like:

UPDATE test SET num = 75, due = now();