import java.sql.*;

/*
You can compile and run this example with a command like:
  javac BasicSample.java && java -cp .:~/path/to/postgresql-9.4.1208.jar BasicSample
You can download the postgres JDBC driver jar from https://jdbc.postgresql.org.
*/
public class BasicSample {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        // Load the postgres JDBC driver.
        Class.forName("org.postgresql.Driver");
        Connection db;
        // Connect to the "bank" database.
        String url = "jdbc:postgresql://127.0.0.1:26257/bank?sslmode=disable";
        if (args.length > 0) {
          url = args[0];
          System.out.printf("url= %s\n", url);
          db = DriverManager.getConnection(url);
        } else {
          System.out.printf("default= %s\n", url);
          db = DriverManager.getConnection(url, "maxroach", "");
        } 

    
        try {
            // Create the "accounts" table.
            db.createStatement().execute("CREATE TABLE IF NOT EXISTS accounts (id INT PRIMARY KEY, balance INT); truncate accounts;");

            // for (int i = 0; i < 1000; i++) {
            // Insert two rows into the "accounts" table.
            //  db.createStatement().execute(String.format("INSERT INTO accounts (id, balance) VALUES (%d, 1000);",i));
            //  //db.createStatement().execute(String.format("INSERT INTO accounts (id, balance) VALUES (%d, 1000) on conflict (id) do update set balance=excluded.balance",i));
            // }

            // dynamic SQL does not alllow batching
            // Statement stmt = db.createStatement();
            // does not convert PreparedStatement stmt = db.prepareStatement("INSERT INTO accounts (id, balance) VALUES (?, 1000) returning id,balance;");
            // works PreparedStatement stmt = db.prepareStatement("INSERT INTO accounts (id, balance) VALUES (?, 1000)");
            // works PreparedStatement stmt = db.prepareStatement("INSERT INTO accounts (id, balance) VALUES (?, 1000) in conflict (id) do update set balance=excluded.balance");
            PreparedStatement stmt = db.prepareStatement("INSERT INTO accounts (id, balance) VALUES (?, 1000)  on conflict (id) do update set balance=excluded.balance");
            for (int i = 1000; i < 2000; i++) {
            // Insert two rows into the "accounts" table.
              stmt.setInt(1, i);
              stmt.addBatch();
            }
            int[] count = stmt.executeBatch();
            for (int i : count){
              System.out.println(i);
            }

            // Print out the balances.
            // System.out.println("Initial balances:");
            // ResultSet res = db.createStatement().executeQuery("SELECT id, balance FROM accounts");
            // while (res.next()) {
            //    System.out.printf("\taccount %s: %s\n", res.getInt("id"), res.getInt("balance"));
            // }
        } finally {
            // Close the database connection.
            db.close();
        }
    }
}