package main

import (
    "math/rand"
    "fmt"
    "database/sql"
    "time"
    _ "github.com/lib/pq"
)

const (
    DB_USER = "postgres"
    DB_PASSWORD = "postgres"
    DB_NAME = "testdb"
)

func randomTimestamp() time.Time {
    randomTime := rand.Int63n(time.Now().Unix())

    randomNow := time.Unix(randomTime, 0)

    return randomNow
}

func randomString() string {
    const charset = "abcdefghijklmnopqrstuvwxyz" +
        "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

    b := make([]byte, rand.Intn(50))
    for i := range b {
        b[i] = charset[rand.Intn(len(charset))]
    }
    return string(b)
}

func main() {
    dbinfo := fmt.Sprintf("user=%s password=%s dbname=%s sslmode=disable",
        DB_USER, DB_PASSWORD, DB_NAME)
    db, err := sql.Open("postgres", dbinfo)
    if err != nil {
        panic(err)
    }
    defer db.Close()

    for i:= 0; i < 10; i++ {
        name := randomString()
        time := randomTimestamp().Format("2006-01-02 15:04:05")
        author := randomString()

        db.QueryRow("insert into post(id, name, date, author) values(DEFAULT, $1, $2, $3);", name, time, author)
    }
}