import java.sql.*;
public class Datenbank {



    static Connection dbConn= null;

    private static boolean loadDriver(String driver){
        //Treiber laden
        try{
            Class.forName(driver);
            return true;
        }
        catch(ClassNotFoundException e)
        {
            System.out.println("Konnte den JDBC-Treiber nicht laden:"+"("+e.getMessage()+")");
            return false;
        }
        }

    private static boolean connect(String URL, String login, String passwort){
        //Verbindung herstellen
        try{
            dbConn= DriverManager.getConnection(URL, login, passwort);
            return true;
            }
        catch(SQLException e){
            System.out.println("Konnte die Verbindung zur Datenbank unter "+login+"nicht herstellen"+"("+e.getMessage()+")");
            return false;
        }
    }

    private static boolean executeSQLStatement(String sqlStatement){
        //Statements ausführen(Create, Insert, Delete, update)
        Statement stmt;
        try{
            stmt=dbConn.createStatement();
            stmt.executeUpdate(sqlStatement);
            stmt.close();
            return true;
        }
        catch(SQLException e){
            e.printStackTrace();
            return false;
        }
    }

    private boolean executeQuery(String query){
        Statement stmt;
        try{
            stmt= this.dbConn.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            ausgabeResult(rs);
            return true;
        }
        catch(SQLException e){
            e.printStackTrace();
            return false;
        }

    }

    private void ausgabeResult(ResultSet rs) {
        // TODO Auto-generated method stub
        try{
            int spalte=rs.getMetaData().getColumnCount();
            while(rs.next()){
                String reihe= new String(" | ");
                for(int i=1; i<=spalte;i++){
                    reihe=reihe.concat(rs.getString(i)+" | ");
                    }
                System.out.println(reihe);
            }
        }
            catch(SQLException e){
                e.printStackTrace();
            }
        }
    private static boolean closeConnection(){
        try{
        dbConn.close();
        dbConn=null;
        return true;
        }
        catch(SQLException e){
            System.out.println("Fehler beim Schließen der Datebankverbindung."+"("+e.getMessage()+")");
            return false;
        }
    }
    public static void main(String[] args){
        String DBdriver= "oracle.jdbc.driver.OracleDriver";
        String dbURL= "jdbc:oracle:thin:@gemini.informatik.uni-augsburg.de:1521:db";
        String dbLogin ="1118590";
        String dbPasswort= "1118598";
        String query1= "CREATE TABLE inventory(partno INTEGER PRIMARY KEY, name CHAR(100), qonhand INTEGER)";
        String query2= "INSERT INTO INVENTORY VALUES (300, 'Screw', 850)";

        loadDriver(DBdriver);
        connect(dbURL,dbLogin,dbPasswort);
        executeSQLStatement(query1);
        executeSQLStatement(query2);
        closeConnection();

    }

    }