pgx_snippet.go

package main

import (
    "context"
    "fmt"
    "os"

    "github.com/jackc/pgtype"
    "github.com/jackc/pgx"
)

func main() {
    conn, err := pgx.Connect(context.Background(), os.Getenv("DATABASE_URL"))
    if err != nil {
        fmt.Fprintf(os.Stderr, "Unable to connection to database: %v\n", err)
        os.Exit(1)
    }
    defer conn.Close(context.Background())

    pctx := context.Background()

    var n pgtype.Interval
    err = conn.QueryRow(pctx, "SELECT now() - pg_last_xact_replay_timestamp() AS time_lag").Scan(&n)
    if err != nil {
        fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
        os.Exit(1)
    }

    nn, err := n.Value()
    if err != nil {
        fmt.Fprintf(os.Stderr, "Value failed: %v\n", err)
        os.Exit(2)
    }

    fmt.Printf("output: %v\n", nn)
}