import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/**
   A bank consisting of multiple bank accounts.
*/
public class Bank
{
   /**
      Finds a customer with a given number and PIN.
      @param customerNumber the customer number
      @param pin the personal identification number
      @return the matching customer, or null if none found
   */
   public Customer findCustomer(int customerNumber, int pin)
         throws SQLException
   {  
      try (Connection conn = SimpleDataSource.getConnection())
      {
         Customer c = null;
         PreparedStatement stat = conn.prepareStatement(
               "SELECT * FROM BankCustomer WHERE Customer_Number = ?");
         stat.setInt(1, customerNumber);
         
         ResultSet result = stat.executeQuery();
         if (result.next() && pin == result.getInt("PIN")) 
         {
            c = new Customer(customerNumber,
                  result.getInt("Checking_Account_Number"),
                  result.getInt("Savings_Account_Number"));
         }
         return c;
      }
   }      
}