package com.roshka.bootcamp;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.PrintWriter;
import java.sql.*;
@WebServlet("/conexion")
public class BD extends HttpServlet {
Connection connection;
public void init() {
try {
Class.forName("org.postgresql.Driver");
connection = DriverManager
.getConnection("jdbc:postgresql://localhost:5432/bootcamp_market",
"postgres", "postgres");
} catch (Exception e) {
e.printStackTrace();
System.err.println(e.getClass().getName()+": "+e.getMessage());
System.exit(0);
}
}
@Override
public void doGet(HttpServletRequest req, HttpServletResponse res) {
try {
Statement stmt = connection.createStatement();
res.setContentType("text/html");
PrintWriter out = res.getWriter();
ResultSet rs = stmt
.executeQuery("select a.nombre, apellido, count(b.cliente_id) Cantidad_factura from cliente a " +
"inner join factura b " +
"on a.id=b.cliente_id " +
"group by a.nombre, a.apellido " +
"order by Cantidad_factura desc;");
out.println("");
out.println("");
while (rs.next()) {
String nombre = rs.getString("nombre");
String apellido = rs.getString("apellido");
int cantidad = rs.getInt("Cantidad_factura");
out.println("----------------------------------------------");
out.println("NOMBRE = \\" + nombre + "
");
out.println("APELLIDO = \\" + apellido + "
");
out.println("CANTIDAD FACTURA = \\" + cantidad + "
");
}
out.println("");
out.println("");
rs.close();
stmt.close();
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
public void destroy() {
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}