Trait MigrationContext

pub trait MigrationContext
where
    Self: MigrationSource<Ctx = Self> + Send + Sync + 'static,
{
    type Exec: Executor;

    const HISTORY_TABLE: &str;

    // Required method
    fn executor(&mut self) -> &mut Self::Exec;

    // Provided methods
    fn apply<'migration, 'conn: 'migration, M>(
        &'conn mut self,
        migration: &'migration M,
    ) -> BoxFuture<'migration, TernResult<AppliedMigration>>
       where M: Migration<Ctx = Self> + Send + Sync + ?Sized { ... }
    fn latest_version(&mut self) -> BoxFuture<'_, TernResult<Option<i64>>> { ... }
    fn previously_applied(
        &mut self,
    ) -> BoxFuture<'_, TernResult<Vec<AppliedMigration>>> { ... }
    fn check_history_table(&mut self) -> BoxFuture<'_, TernResult<()>> { ... }
    fn drop_history_table(&mut self) -> BoxFuture<'_, TernResult<()>> { ... }
    fn insert_applied<'migration, 'conn: 'migration>(
        &'conn mut self,
        applied: &'migration AppliedMigration,
    ) -> BoxFuture<'migration, TernResult<()>> { ... }
    fn upsert_applied<'migration, 'conn: 'migration>(
        &'conn mut self,
        applied: &'migration AppliedMigration,
    ) -> BoxFuture<'migration, TernResult<()>> { ... }
}

The context in which a migration run occurs.

Required Associated Constants

const HISTORY_TABLE: &str

The name of the table in the database that tracks the history of this migration set.

It defaults to _tern_migrations in the default schema for the database driver if using the derive macro for this trait.

Required Associated Types

type Exec: Executor

The type for executing queries in a migration run.

Required Methods

fn executor(&mut self) -> &mut Self::Exec

A reference to the underlying Executor.

Provided Methods

fn apply<'migration, 'conn: 'migration, M>( &'conn mut self, migration: &'migration M, ) -> BoxFuture<'migration, TernResult<AppliedMigration>>

where M: Migration<Ctx = Self> + Send + Sync + ?Sized,

For a migration that is capable of building its query in this migration context, this builds the query, applies the migration, then updates the schema history table after.

fn latest_version(&mut self) -> BoxFuture<'_, TernResult<Option<i64>>>

Gets the version of the most recently applied migration.

fn previously_applied( &mut self, ) -> BoxFuture<'_, TernResult<Vec<AppliedMigration>>>

Get all previously applied migrations.

fn check_history_table(&mut self) -> BoxFuture<'_, TernResult<()>>

Check that the history table exists and create it if not.

fn drop_history_table(&mut self) -> BoxFuture<'_, TernResult<()>>

Drop the history table if requested.

fn insert_applied<'migration, 'conn: 'migration>( &'conn mut self, applied: &'migration AppliedMigration, ) -> BoxFuture<'migration, TernResult<()>>

Insert an applied migration.

fn upsert_applied<'migration, 'conn: 'migration>( &'conn mut self, applied: &'migration AppliedMigration, ) -> BoxFuture<'migration, TernResult<()>>

Upsert applied migrations.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors