Java PreparedStatement

PreparedStatement is a class in Java that is used to execute parameterized SQL queries. It is an interface that extends the Statement interface and provides several advantages over the Statement interface.

The PreparedStatement interface provides the following benefits:

1. Security: Prepared statements help in preventing SQL injection attacks by allowing the separation of input data from the SQL query.

2. Performance: Prepared statements are pre-compiled and cached in the database server, which leads to faster execution of the same query with different parameters.

3. Reusability: A prepared statement can be reused with different parameters, which reduces the overhead of creating a new SQL statement every time.

To create a PreparedStatement object, the following steps are required:

1. Create a Connection object to establish a database connection.

2. Prepare the SQL query using the prepareStatement() method of the Connection object.

3. Set the parameter values for the prepared statement using the setXXX() methods.

4. Execute the prepared statement using the execute() or executeUpdate() methods.

5. Close the prepared statement and the database connection using the close() method.

Here is an example of using PreparedStatement:

String query = "SELECT * FROM employees WHERE department = ?";
PreparedStatement pstmt = conn.prepareStatement(query);
pstmt.setString(1, "Sales");
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
    // process result set
}
pstmt.close();
conn.close();

In this example, a PreparedStatement object is created to execute a SELECT query with a parameter. The parameter value is set using the setString() method, and the query is executed using the executeQuery() method. Finally, the prepared statement and the database connection are closed using the close() method.