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_filtered(&self) -> Box<[(&'static str, Value)]>;
    fn row_full(&self) -> Row;
    fn from_row(row: RowLabeled) -> Result<Self>
       where Self: Sized;

    // Provided methods
    fn row_labeled(&self) -> RowLabeled { ... }
    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>>> { ... }
    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_filtered(&self) -> Box<[(&'static str, Value)]>

Column name-value pairs for persistence (excludes ignored/default fields).

fn row_full(&self) -> Row

Full row representation including all persisted columns.

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

where Self: Sized,

Reconstruct Self from a labeled row.

Fails if columns are missing or type conversion fails.

Provided Methods

fn row_labeled(&self) -> RowLabeled

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>>>

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", so this trait is not object safe.

Implementors