How does the PreparedStatement object work in the context of interacting with a database?

PreparedStatement is an object in Java used to execute precompiled SQL queries against a database.

How it works:

• When creating a PreparedStatement, the SQL query is provided with placeholder parameters (e.g., ?).
• The query is compiled once on the database side.
• When executing, different parameter values can be substituted repeatedly without recompiling.

Advantages:

• Improved performance for repeated queries.
• Protection against SQL injection, as parameters are passed separately and do not affect the query structure.

Example of usage:

String sql = "SELECT * FROM users WHERE username = ? AND status = ?";
PreparedStatement ps = connection.prepareStatement(sql);
ps.setString(1, "john_doe");
ps.setString(2, "active");
ResultSet rs = ps.executeQuery();

Here, ? are parameters replaced by setString methods. This approach is safer and more efficient than string concatenation for forming SQL.