Model Declaration

derive(Model) macro

At the heart of the orm is the derive macro turning a rust struct into a db model.

It uses #[rorm(..)] attributes on fields to provide additional information.

For example a database needs to know how much space a string is expected to occupy:

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(max_length = 255)]
    username: String,
}

These attributes can be stacked on a field or multiple annotations can be set in a single attribute:

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(unique)]
    #[rorm(max_length = 255)]
    username: String,

    #[rorm(max_length = 255, unique)]
    email: String,
}

Annotations

Annotations are the extra information defined in the #[rorm(..)] attributes. Some of them map directly to SQL annotations while other are purely for orm purposes.

autoincrement

The autoincrement annotation instructs the database to populate the field using a running counter when creating the rows of this model.

use rorm::prelude::*;

#[derive(Model)]
struct Order {
    .. // fields missing to be functional

    #[rorm(autoincrement)]
    order_number: i64,
}

auto_create_time and auto_update_time

You can utilize the annotations auto_create_time and auto_update_time to automatically set the current time on creation or on update of the model to the annotated field.

use chrono::{DateTime, Utc};
use rorm::prelude::*;

#[derive(Model)]
struct File {
    .. // fields missing to be functional

    #[rorm(auto_create_time)]
    created: DateTime<Utc>,

    #[rorm(auto_update_time)]
    modified: DateTime<Utc>,
}

default

A default value to populate this field with, if a new model instance is created without mentioning this field. Note that you need a patch struct to utilize its advantage in the Rust code.

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(default = false)]
    is_admin: bool,
}

id

Shorthand for both primary_key and autoincrement

use rorm::prelude::*;

#[derive(Model)]
struct User {
    #[rorm(id)]
    id: i64,
}

index

rorm currently supports standard indexes and composite indexes.

To create a standard index:

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(index, max_length = 255)]
    name: String,
}

---

To create a composite index, include the name property:

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(index("name"), max_length = 255)]
    first_name: String,


    #[rorm(index("name"), max_length = 255)]
    last_name: String,
}

Info

This will create a composite index in the order of occurrences of the index, so for the example above: first_name, last_name.

To change the order in the index creation, use the priority property:

use rorm::prelude::*;

#[derive(Model)]
struct User {
.. // fields missing to be functional

    #[rorm(index("name", priority = 2), max_length = 255)]
    first_name: String,


    #[rorm(index("name", priority = 1), max_length = 255)]
    last_name: String,
}

max_length

Specify the maximum length a String can have. This is required for every string.

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(max_length = 255)]
    username: String,
}

on_delete, on_update

These annotations specify the policy for the relations that are applied on either delete or update.

Possible values are: - Restrict - Cascade - SetNull - SetDefault

use rorm::prelude::*;

#[derive(Model)]
struct Post {
    #[rorm(id)]
    id: i64,

    #[rorm(on_delete = "Cascade", on_update = "SetNull")]
    user: Option<ForeignModel<User>>,
}

#[derive(Model)]
struct User {
    #[rorm(primary_key)]
    username: String,
}

primary_key

Marks a field as primary key in the database. As primary keys are by default unique, the unique annotation is not available for fields that have the primary_key annotation set.

use rorm::prelude::*;

#[derive(Model)]
struct User {
    #[rorm(primary_key)]
    username: String,
}

rename

With this annotation, rorm is instructed to use the provided field name instead of real name.

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(rename = "user_name")]
    username: String,
}

unique

With this annotation, rorm is instructed to use the provided field name instead of real name.

use rorm::prelude::*;

#[derive(Model)]
struct User {
    .. // fields missing to be functional

    #[rorm(unique)]
    chosen_number: i16,
}

Info

This annotation is not required on fields with the primary_key annotation, as primary_key enforces uniqueness on database level.