使用golang连接到google cloud VM实例上的postgres？

go get -u github.com/lib/pq

package main

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

    _ "github.com/lib/pq"
)

func main() {
    // PostgreSQL connection parameters
    host := "YOUR_VM_EXTERNAL_IP"
    port := 5432 // Default PostgreSQL port
    user := "YOUR_DB_USERNAME"
    password := "YOUR_DB_PASSWORD"
    dbname := "YOUR_DB_NAME"

    // Connection string
    psqlInfo := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
        host, port, user, password, dbname)

    // Open a connection to the database
    db, err := sql.Open("postgres", psqlInfo)
    if err != nil {
        log.Fatalf("Error opening database: %v\n", err)
    }
    defer db.Close()

    // Verify the connection
    err = db.Ping()
    if err != nil {
        log.Fatalf("Error connecting to the database: %v\n", err)
    }

    fmt.Println("Successfully connected to the database!")

    // Execute a query
    rows, err := db.Query("SELECT id, name FROM your_table")
    if err != nil {
        log.Fatalf("Error executing query: %v\n", err)
    }
    defer rows.Close()

    // Iterate through the result set
    for rows.Next() {
        var id int
        var name string
        err := rows.Scan(&id, &name)
        if err != nil {
            log.Fatalf("Error scanning row: %v\n", err)
        }
        fmt.Printf("ID: %d, Name: %s\n", id, name)
    }

    // Check for errors from iterating over rows
    err = rows.Err()
    if err != nil {
        log.Fatalf("Error iterating over rows: %v\n", err)
    }
}

go run main.go