PolarDB:Connect to a global database network

Add the driver dependency to pom.xml:

<dependency>
  <groupId>org.postgresql</groupId>
  <artifactId>postgresql</artifactId>
  <version>42.2.18</version>
</dependency>

Connect to the cluster. Replace <HOST>, <PORT>, <USER>, <PASSWORD>, <DATABASE>, <YOUR_TABLE_NAME>, and <YOUR_TABLE_COLUMN_NAME> with your actual values.

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

public class PolarDBConnection {
    public static void main(String[] args) {
        String url = "jdbc:postgresql://<HOST>:<PORT>/<DATABASE>";
        String user = "<USER>";
        String password = "<PASSWORD>";

        try {
            // Load the PostgreSQL JDBC driver.
            Class.forName("org.postgresql.Driver");

            // Establish the connection.
            Connection conn = DriverManager.getConnection(url, user, password);

            // Execute a query.
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM <YOUR_TABLE_NAME>");

            // Process results.
            while (rs.next()) {
                System.out.println(rs.getString("<YOUR_TABLE_COLUMN_NAME>"));
            }

            // Close resources.
            rs.close();
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Install the library:

pip3 install psycopg2-binary

Connect to the cluster. Replace <HOST>, <PORT>, <USER>, <PASSWORD>, <DATABASE>, and <YOUR_TABLE_NAME> with your actual values.

import psycopg2

try:
    conn = psycopg2.connect(
        host="<HOST>",        # Cluster endpoint
        database="<DATABASE>",
        user="<USER>",
        password="<PASSWORD>",
        port="<PORT>"
    )

    cursor = conn.cursor()
    cursor.execute("SELECT * FROM <YOUR_TABLE_NAME>")

    records = cursor.fetchall()
    for record in records:
        print(record)

except Exception as e:
    print("Error:", e)
finally:
    if 'cursor' in locals():
        cursor.close()
    if 'conn' in locals():
        conn.close()

Install the driver:

go get -u github.com/lib/pq

Connect to the cluster. Replace <HOST>, <PORT>, <USER>, <PASSWORD>, <DATABASE>, and <YOUR_TABLE_NAME> with your actual values.

package main

import (
    "database/sql"
    "fmt"
    "log"

    _ "github.com/lib/pq" // Initialize the PostgreSQL driver.
)

func main() {
    connStr := "user=<USER> password=<PASSWORD> dbname=<DATABASE> host=<HOST> port=<PORT> sslmode=disable"

    db, err := sql.Open("postgres", connStr)
    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()

    // Verify the connection.
    if err = db.Ping(); err != nil {
        log.Fatal(err)
    }
    fmt.Println("Connected to PostgreSQL!")

    rows, err := db.Query("SELECT * FROM <YOUR_TABLE_NAME>")
    if err != nil {
        log.Fatal(err)
    }
    defer rows.Close()
}