Trait Entity 

pub trait Entity {
    type PrimaryKey<'a>
       where Self: 'a;

    // Required methods
    fn table() -> &'static TableRef;
    fn columns() -> &'static [ColumnDef];
    fn primary_key_def() -> &'static [&'static ColumnDef];
    fn primary_key(&self) -> Self::PrimaryKey<'_>;
    fn primary_key_expr(&self) -> impl Expression;
    fn unique_defs(    ) -> impl ExactSizeIterator<Item = impl ExactSizeIterator<Item = &'static ColumnDef>>;
    fn row_values(&self) -> RowValues;
    fn from_row(row: Row) -> Result<Self>
       where Self: Sized;

    // Provided methods
    fn row(&self) -> Row { ... }
    fn create_table(
        executor: &mut impl Executor,
        if_not_exists: bool,
        create_schema: bool,
    ) -> impl Future<Output = Result<()>> + Send
       where Self: Sized { ... }
    fn drop_table(
        executor: &mut impl Executor,
        if_exists: bool,
        drop_schema: bool,
    ) -> impl Future<Output = Result<()>> + Send
       where Self: Sized { ... }
    fn insert_one(
        executor: &mut impl Executor,
        entity: &impl Entity,
    ) -> impl Future<Output = Result<RowsAffected>> + Send { ... }
    fn insert_many<'a, It>(
        executor: &mut impl Executor,
        items: It,
    ) -> impl Future<Output = Result<RowsAffected>> + Send
       where Self: Sized + 'a,
             It: IntoIterator<Item = &'a Self> + Send,
             <It as IntoIterator>::IntoIter: Send { ... }
    fn prepare_find<Exec: Executor>(
        executor: &mut Exec,
        condition: impl Expression,
        limit: Option<u32>,
    ) -> impl Future<Output = Result<Query<Exec::Driver>>> + Send { ... }
    fn find_one(
        executor: &mut impl Executor,
        condition: impl Expression,
    ) -> impl Future<Output = Result<Option<Self>>> + Send
       where Self: Sized { ... }
    fn find_many(
        executor: &mut impl Executor,
        condition: impl Expression,
        limit: Option<u32>,
    ) -> impl Stream<Item = Result<Self>> + Send
       where Self: Sized { ... }
    fn delete_many(
        executor: &mut impl Executor,
        condition: impl Expression,
    ) -> impl Future<Output = Result<RowsAffected>> + Send
       where Self: Sized { ... }
    fn save(
        &self,
        executor: &mut impl Executor,
    ) -> impl Future<Output = Result<()>> + Send
       where Self: Sized { ... }
    fn delete(
        &self,
        executor: &mut impl Executor,
    ) -> impl Future<Output = Result<()>> + Send
       where Self: Sized { ... }
}

Database entity mapping.

Use #[derive(Entity)] to implement this trait.

Required Associated Types

type PrimaryKey<'a> where Self: 'a

Primary key type. A tuple of field types (or single type) forming the PK.

Required Methods

fn table() -> &'static TableRef

Table reference matching the #[tank(...)] attributes.

fn columns() -> &'static [ColumnDef]

All column definitions in declaration order.

fn primary_key_def() -> &'static [&'static ColumnDef]

Primary key column definitions. Empty if no PK defined.

fn primary_key(&self) -> Self::PrimaryKey<'_>

Extract PK value(s) from self.

fn primary_key_expr(&self) -> impl Expression

Build an expression matching the PK of self.

fn unique_defs() -> impl ExactSizeIterator<Item = impl ExactSizeIterator<Item = &'static ColumnDef>>

Unique constraint definitions.

fn row_values(&self) -> RowValues

Full row representation including all persisted columns.

fn from_row(row: Row) -> Result<Self>

where Self: Sized,

Reconstruct Self from a labeled row.

Fails if columns are missing or type conversion fails.

Provided Methods

fn row(&self) -> Row

Full row representation with column labels.

fn create_table( executor: &mut impl Executor, if_not_exists: bool, create_schema: bool, ) -> impl Future<Output = Result<()>> + Send

where Self: Sized,

Create table (and optional schema).

• if_not_exists: Emits IF NOT EXISTS if supported.
• create_schema: Attempts schema creation first.

fn drop_table( executor: &mut impl Executor, if_exists: bool, drop_schema: bool, ) -> impl Future<Output = Result<()>> + Send

where Self: Sized,

Drop the table (and optional schema).

• if_exists: Emits IF EXISTS if supported.
• drop_schema: Drops schema after table removal (if empty).

fn insert_one( executor: &mut impl Executor, entity: &impl Entity, ) -> impl Future<Output = Result<RowsAffected>> + Send

Insert a single entity.

fn insert_many<'a, It>( executor: &mut impl Executor, items: It, ) -> impl Future<Output = Result<RowsAffected>> + Send

where Self: Sized + 'a, It: IntoIterator<Item = &'a Self> + Send, <It as IntoIterator>::IntoIter: Send,

Bulk insert entities.

fn prepare_find<Exec: Executor>( executor: &mut Exec, condition: impl Expression, limit: Option<u32>, ) -> impl Future<Output = Result<Query<Exec::Driver>>> + Send

Prepare (but do not yet run) a SQL select query.

Returns the prepared statement.

fn find_one( executor: &mut impl Executor, condition: impl Expression, ) -> impl Future<Output = Result<Option<Self>>> + Send

where Self: Sized,

Finds the first entity matching a condition expression.

Returns Ok(None) if no row matches.

fn find_many( executor: &mut impl Executor, condition: impl Expression, limit: Option<u32>, ) -> impl Stream<Item = Result<Self>> + Send

where Self: Sized,

Streams entities matching a condition.

limit restricts the maximum number of rows returned at a database level if Some (if supported by the driver, unlimited otherwise).

fn delete_many( executor: &mut impl Executor, condition: impl Expression, ) -> impl Future<Output = Result<RowsAffected>> + Send

where Self: Sized,

Deletes all entities matching a condition.

Returns the number of deleted rows.

fn save( &self, executor: &mut impl Executor, ) -> impl Future<Output = Result<()>> + Send

where Self: Sized,

Saves the entity (insert or update if available) based on primary key presence.

Errors:

• Missing PK in the table.
• Execution failures from underlying driver.

fn delete( &self, executor: &mut impl Executor, ) -> impl Future<Output = Result<()>> + Send

where Self: Sized,

Deletes this entity instance via its primary key.

Errors:

• Missing PK in the table.
• If not exactly one row was deleted.
• Execution failures from underlying driver.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors