SimpleExpr::Constant conversion to string drops second fractions

[davidhewitt]

Looking at

sea-query/src/backend/query_builder.rs

Lines 1076 to 1087 in 1928f23

	#[cfg(feature = "with-chrono")]
	Value::ChronoDateTimeUtc(Some(v)) => {
	write!(s, "'{}'", v.format("%Y-%m-%d %H:%M:%S %:z")).unwrap()
	}
	#[cfg(feature = "with-chrono")]
	Value::ChronoDateTimeLocal(Some(v)) => {
	write!(s, "'{}'", v.format("%Y-%m-%d %H:%M:%S %:z")).unwrap()
	}
	#[cfg(feature = "with-chrono")]
	Value::ChronoDateTimeWithTimeZone(Some(v)) => {
	write!(s, "'{}'", v.format("%Y-%m-%d %H:%M:%S %:z")).unwrap()
	}

I think these format strings don't account for second fractions. I hit a case where I was trying to feed constant date-times into a query and the microseconds were getting dropped, I believe the cause was in these lines.