Struct AsyncMigrationHarness 

pub struct AsyncMigrationHarness<C> { /* private fields */ }

Available on crate feature migrations only.

A diesel-migration MigrationHarness to run migrations via an AsyncConnection

Internally this harness is using tokio::task::block_in_place and AsyncConnectionWrapper to utilize sync Diesel’s migration infrastructure. For most applications this shouldn’t be problematic as migrations are usually run at application startup and most applications default to use the multithreaded tokio runtime. In turn this also means that you cannot use this migration harness if you use the current thread variant of the tokio runtime or if you run migrations in a very special setup (e.g by using tokio::select! or tokio::join! on a future produced by running the migrations). Consider manually construct a blocking task via tokio::task::spawn_blocking instead.

Example

use diesel_async::AsyncMigrationHarness;
use diesel_migrations::{FileBasedMigrations, MigrationHarness};

let mut connection = connection_no_data().await;

// Alternativly use `diesel_migrations::embed_migrations!()`
// to get a list of migrations
let migrations = FileBasedMigrations::find_migrations_directory()?;

let mut harness = AsyncMigrationHarness::new(connection);
harness.run_pending_migrations(migrations)?;
// get back the connection from the harness
let connection = harness.into_inner();

Example with pool

let config = AsyncDieselConnectionManager::<diesel_async::AsyncPgConnection>::new(db_url);
use diesel_async::pooled_connection::deadpool::Pool;
use diesel_async::AsyncMigrationHarness;
use diesel_migrations::{FileBasedMigrations, MigrationHarness};

// Alternativly use `diesel_migrations::embed_migrations!()`
// to get a list of migrations
let migrations = FileBasedMigrations::find_migrations_directory()?;

let pool = Pool::builder(get_config()).build()?;
let mut harness = AsyncMigrationHarness::new(pool.get().await?);
harness.run_pending_migrations(migrations)?;

Implementations

impl<C> AsyncMigrationHarness<C>

where C: AsyncConnection,

pub fn new(connection: C) -> Self

Construct a new AsyncMigrationHarness from a given connection

pub fn into_inner(self) -> C

Return the connection stored inside this instance of AsyncMigrationHarness

Trait Implementations

impl<C> From<C> for AsyncMigrationHarness<C>

where C: AsyncConnection,

fn from(value: C) -> Self

Converts to this type from the input type.

impl<C> MigrationHarness<<C as AsyncConnectionCore>::Backend> for AsyncMigrationHarness<C>

where C: AsyncConnection, AsyncConnectionWrapper<C, Tokio>: Connection<Backend = C::Backend> + MigrationHarness<C::Backend>,

fn run_migration( &mut self, migration: &dyn Migration<C::Backend>, ) -> Result<MigrationVersion<'static>>

Apply a single migration

fn revert_migration( &mut self, migration: &dyn Migration<C::Backend>, ) -> Result<MigrationVersion<'static>>

Revert a single migration

fn applied_migrations(&mut self) -> Result<Vec<MigrationVersion<'static>>>

Get a list of already applied migration versions

fn has_pending_migration<S>( &mut self, source: S, ) -> Result<bool, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Checks if the database represented by the current harness has unapplied migrations

fn run_pending_migrations<S>( &mut self, source: S, ) -> Result<Vec<MigrationVersion<'_>>, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Execute all unapplied migrations for a given migration source

fn run_next_migration<S>( &mut self, source: S, ) -> Result<MigrationVersion<'_>, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Execute the next migration from the given migration source

fn revert_all_migrations<S>( &mut self, source: S, ) -> Result<Vec<MigrationVersion<'_>>, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Revert all applied migrations from a given migration source

fn revert_last_migration<S>( &mut self, source: S, ) -> Result<MigrationVersion<'static>, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Revert the last migration from a given migration source

fn pending_migrations<S>( &mut self, source: S, ) -> Result<Vec<Box<dyn Migration<DB>>>, Box<dyn Error + Sync + Send>>

where S: MigrationSource<DB>,

Get a list of non applied migrations for a specific migration source