Crate gremlin_orm

gremlin-orm

This crate provides a lightweight, type-safe ORM for PostgreSQL in Rust, focusing on minimal boilerplate and compile-time query safety.

Example

use gremlin_orm::Entity;

#[derive(Entity, sqlx::FromRow)]
#[orm(table = "public.artist")]
struct Artist {
    #[orm(pk, generated)]
    id: i32,
    name: String,
    #[orm(generated)]
    slug: String,
}

Annotations

The #[orm(...)] attribute supports both struct-level and field-level annotations to control code generation and database mapping.

Struct-level Annotations

• #[orm(table = "schema.table")]: Specifies the database table for the entity.

Field-level Annotations

• #[orm(pk)]: Marks the field as a primary key. Multiple fields can be marked as primary keys for composite keys.
• #[orm(generated)]: Indicates the field is auto-generated by the database (e.g., auto-increment or computed columns). Such fields are excluded from inserts and updates.
• #[orm(deref)]: Used for optional/reference types (e.g., Option<T>, &str, etc.), allowing the macro to handle dereferencing when generating queries.
• #[orm(default)]: Allows the field to use a default value when inserting, by wrapping it in Defaultable<T>.

Traits Overview

InsertableEntity

For types that can be inserted into the database. An “Insertable” struct is generated for each entity, containing only the fields that should be provided on insert.

Field annotated with the default annotation are wrappedin Defaultable. Indicating if the default value should be used, or the provided one

FetchableEntity

For types that can be fetched by primary key(s) from the database. A “Pk” struct is generated for each entity, containing only the primary key fields.

StreamableEntity

For types that can be streamed (selected) from the database. This trait is implemented for the entity struct, allowing you to stream all rows from the table.

UpdatableEntity

For types that can be updated in the database. An “Updatable” struct is generated for each entity, containing the primary key(s) and updatable fields.

DeletableEntity

For types that can be deleted from the database. This trait is implemented for the entity struct, allowing you to delete a row by its primary key(s).

Enums

Defaultable

Used for inserting values, use either the default or the provided value

Traits

DeletableEntity

Trait for types that can be deleted from the database. This trait is implemented for the entity struct, allowing you to delete a row by its primary key(s).

FetchableEntity

Trait for types that can be fetched by primary key(s) from the database. A “Pk” struct is generated for each entity, containing only the primary key fields.

InsertableEntity

Trait for types that can be inserted into the database. An “Insertable” struct is generated for each entity, containing only the fields that should be provided on insert.

Stream

A stream of values produced asynchronously.

StreamableEntity

Trait for types that can be streamed (selected) from the database. This trait is implemented for the entity struct, allowing you to stream all rows from the table.

UpdatableEntity

Trait for types that can be updated in the database. An “Updatable” struct is generated for each entity, containing the primary key(s) and updatable fields.

Derive Macros

Entity

Generate the entity