How to convert DateTime::now() into NaiveDateTime? - datetime

Question

I'm using Diesel and chrono. In my model I have a field of type NaiveDateTime which contains the now(). However, NaiveDateTime doesn't have the function now() or a similar one whereas DateTime does:
Utc::now()
How can I convert Utc::now() into NaiveDateTime?

Answer 1

Utc::now() returns a DateTime<Utc>. You could click into the documentation of DateTime<T> and search for NaiveDateTime. You should find that there are two methods that will return a NaiveDateTime:
fn naive_utc(&self) -> NaiveDateTime
  Returns a view to the naive UTC datetime.
fn naive_local(&self) -> NaiveDateTime
  Returns a view to the naive local datetime.
For instance, if you need the timestamp in UTC:
let naive_date_time = Utc::now().naive_utc();
Note that since you are using diesel, you could use diesel::dsl::now instead, which will evaluate to CURRENT_TIMESTAMP on the SQL side.
//! ```cargo
//! [dependencies]
//! diesel = { version = "1", features = ["sqlite"] }
//! ```
#[macro_use]
extern crate diesel;
use diesel::prelude::*;
use diesel::dsl;
table! {
posts (id) {
id -> Integer,
content -> Text,
published -> Timestamp,
}
}
fn main() {
let conn = SqliteConnection::establish("test.db")
.expect("Cannot open database");
diesel::insert_into(posts::table)
.values((
posts::content.eq("hello"),
posts::published.eq(dsl::now), // <------------------
))
.execute(&conn)
.expect("Insertion failed");
}