connecting to database(postgres) with java in intellij

Question

I want to write a code to get my queries from input and run it and show me the result.I have to connect to database in my code. I connected to postgres by intellij database extension and my queries run in the console.

but i want to do that in my code(i mean get the queries from user and run it). is it possible to use this database connection and run queries on it?

i got connected successfully by this code too :

Connection con = DriverManager.getConnection("jdbc:postgresql://localhost:5432/db","postgres", "pass");

and i wrote some queries. all query types(such as update , delete , insert , ...) run and the result is visible in the pgadmin but i want to have the result in my java code

Answer 1

Here is an example to run a query with JDBC. you can download the JDBC here https://jdbc.postgresql.org/download.html and added to your classpath

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class PostgreSqlExample {
    public static void main(String[] args) {
        try (Connection connection = DriverManager.getConnection("jdbc:postgresql://localhost:5432/example", "postgres", "postgres")) {

            System.out.println("Java JDBC PostgreSQL Example");

            System.out.println("Connected to PostgreSQL database!");
            Statement statement = connection.createStatement();
            System.out.println("Reading car records...");
            System.out.printf("%-30.30s  %-30.30s%n", "Model", "Price");
            ResultSet resultSet = statement.executeQuery("SELECT * FROM public.cars");
            while (resultSet.next()) {
                System.out.printf("%-30.30s  %-30.30s%n", resultSet.getString("model"), resultSet.getString("price"));
            }

        } /*catch (ClassNotFoundException e) {
            System.out.println("PostgreSQL JDBC driver not found.");
            e.printStackTrace();
        }*/ catch (SQLException e) {
            System.out.println("Connection failure.");
            e.printStackTrace();
        }
    }
}