Crate butane 

An experimental ORM for Rust with a focus on simplicity and on writing Rust, not SQL Butane takes an object-oriented approach to database operations. It may be thought of as much as an object-persistence system as an ORM. The fact that it is backed by a SQL database is mostly an implementation detail to the API consumer.

Modules

custom

For supporting additional types with the Pg backend (or other future backends).

db

Types, traits, and methods for interacting with a database.

internal

Internals used in macro-generated code.

migrations

For working with migrations. If using the butane CLI tool, it is not necessary to use these types directly.

prelude

Prelude module to improve ergonomics. Brings certain traits into scope. This module is for sync operation. For asynchronous, see super::prelude_async.

prelude_async

Prelude module to improve ergonomics in async operation. Brings certain traits into scope.

query

Types to support database queries. Most users will use the query!, filter!, and find! macros instead of using this module directly.

Macros

colname

Type-safe way to refer to a column name. Use as colname!(MODEL_TYPE, FIELD_NAME). E.g. For a model type Foo with a field bar, colname!(Foo, bar) would return “bar”, but colname!(Foo, bat)would be a compiler error (assumingFoo` does not have such a field.

filter

Macro to construct a BoolExpr (for use with a Query) from an expression with Rust syntax.

find

Finds a specific database object.

find_async

Like find, but for async.

query

Constructs a filtered database query.

Structs

AutoPk

Wrapper around a PrimaryKeyType to indicate the the primary key will be initialized automatically when the object is created in the database. Dereferences to an Option<T>.

ForeignKey

Used to implement a relationship between models.

Many

Used to implement a many-to-many relationship between models.

Enums

Error

Butane errors.

SqlType

Enumeration of the types a database value may take.

SqlVal

A database value.

SqlValRef

Traits

AsPrimaryKey

Trait for referencing the primary key for a given model. Used to implement ForeignKey equality tests.

DataObject

An object in the database.

DataObjectOpsAsync

DataObject operations that require a live database connection.

DataObjectOpsSync

DataObject operations that require a live database connection.

DataResult

A type which may be the result of a database query.

FieldType

Type suitable for being a database column.

ForeignKeyOpsAsync

ForeignKey operations which require a Connection.

ForeignKeyOpsSync

ForeignKey operations which require a Connection.

FromSql

Used to convert a SqlVal or SqlValRef into another type.

ManyOpsAsync

Many operations which require a Connection.

ManyOpsSync

Many operations which require a Connection.

PrimaryKeyType

Marker trait for a type suitable for being a primary key

ToSql

Used to convert another type to a SqlVal or SqlValRef.

Type Aliases

Result

Result type that uses crate::Error.

Attribute Macros

butane_type

Attribute macro which marks a type as being available to butane for use in models.

dataresult

Attribute macro which generates an implementation of DataResult. Continuing with our blog post example from model, we could create a DataResult with only some of the fields from Post (to avoid fetching all of them in a query).

model

Attribute macro which marks a struct as being a data model and generates an implementation of DataObject. This macro will also write information to disk at compile time necessary to generate migrations

Derive Macros

FieldType

Derive macro for FieldType. Produces a String field for simple enums, otherwise uses a JSON field if json feature is enabled. E.g.

PrimaryKeyType

Derive macro for marker trait PrimaryKeyType. E.g.