Step by Step solution about How to resolve the algorithm Parameterized SQL statement step by step in the Java programming language

The Java code you provided demonstrates how to use a PreparedStatement to update data in a database. The PreparedStatement interface provides a pre-compiled SQL statement that can be executed multiple times with different values for the parameters. This is more efficient than creating a new Statement object each time you need to execute a query.

The code begins by creating a Connection object to the database. This is done by calling the DriverManager.getConnection() method and passing in the database URL, username, and password.

Once a connection has been established, a PreparedStatement object is created by calling the Connection.prepareStatement() method. The SQL statement to be executed is passed in as a parameter to this method. In this case, the SQL statement is an UPDATE statement that will update the name, score, and active status of a player in the players table.

The next step is to set the values of the parameters in the PreparedStatement. This is done by calling the setString(), setInt(), and setBoolean() methods of the PreparedStatement object. In this case, the values for the name, score, and active status are set to "Smith, Steve", 42, and true, respectively.

Once the values of the parameters have been set, the PreparedStatement.executeUpdate() method is called to execute the SQL statement. This method will return the number of rows that were affected by the update statement.

In this case, the expected return value is 1, since only one row in the players table should be updated. If the update statement is successful, the return value will be 1. Otherwise, the return value will be 0.

The code concludes by catching any exceptions that may occur during the execution of the code and printing them to the console.

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
 
public class DBDemo{
   private String protocol; //set this to some connection protocol like "jdbc:sqlserver://"
   private String dbName;   //set this to the name of your database
   private String username;
   private String password;

   PreparedStatement query;
 
   public int setUpAndExecPS(){
      try {
         Connection conn = DriverManager.getConnection(protocol + dbName, username, password);

         query = conn.prepareStatement(
            "UPDATE players SET name = ?, score = ?, active = ? WHERE jerseyNum = ?");
 
         query.setString(1, "Smith, Steve");//automatically sanitizes and adds quotes
         query.setInt(2, 42);
         query.setBoolean(3, true);
         query.setInt(4, 99);
         //there are similar methods for other SQL types in PerparedStatement
         return query.executeUpdate();//returns the number of rows changed
         //PreparedStatement.executeQuery() will return a java.sql.ResultSet,
         //execute() will simply return a boolean saying whether it succeeded or not

      } catch (Exception e) {
         e.printStackTrace();
      }

      return 0;
   }
}