Notes

package Week3;

import java.util.Scanner;
import userlib.TextIO;
import wk3.db.DBApp;

public class NorthwindApp {

// application main method
public static void main(String[] args) {
// general tasks: preparation
DBApp dba = null;
dba = new DBApp(DBApp.DRIVER_POSTGRESQL);

String dbName = "northwind";
String userName = "postgres";
String password = "admin"; //change password to your password. default is postgres
boolean ok = dba.connect(dbName, userName, password);

if (!ok)
System.exit(1);

// application specific tasks
try {
String result = "";
Scanner sc = new Scanner(System.in);
System.out.println("Please select the query");
String sql = sc.nextLine(); //obtain query from keyboard
System.out.println("Executing query: " + sql);

String str = sql.substring(0, 6).toLowerCase(); //check the function
switch(str) {
case "select":
result = dba.select(sql);
System.out.println("Execution completed.");
break;
case "insert":
dba.insert(sql);
System.out.println("Execution completed.");
break;
case "update":
dba.update(sql);
System.out.println("Execution completed.");
break;
case "delete":
dba.delete(sql);
System.out.println("Execution completed.");
break;
default:
System.out.println("Querry not found");
}
sc.close();

// write result to file
String userDir = System.getProperty("user.dir");
String fileChar = System.getProperty("file.separator");
String file = userDir+fileChar+"sqloutput.html";

// OR String file = "sqloutput.html"

TextIO.writeFile(file);
TextIO.putln("<b>Result for query:</b><br>" + sql);
TextIO.putln("<p>");
TextIO.putln(result);
System.out.println("Written result to file " + file);
TextIO.writeStandardOutput();
} catch (Exception e) {
e.printStackTrace();
}
// general tasks: close
dba.close();
}
}