Trait DatabaseSchema 

pub trait DatabaseSchema<M, A = AccessControlList>
where
    M: MemoryProvider,
    A: AccessControl,
{
    // Required methods
    fn select(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &str,
        query: Query,
    ) -> DbmsResult<Vec<Vec<(ColumnDef, Value)>>>;
    fn aggregate(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &str,
        query: Query,
        aggregates: &[AggregateFunction],
    ) -> DbmsResult<Vec<AggregatedRow>>;
    fn referenced_tables(
        &self,
        table: &'static str,
    ) -> Vec<(&'static str, Vec<&'static str>)>;
    fn insert(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &'static str,
        record_values: &[(ColumnDef, Value)],
    ) -> DbmsResult<()>;
    fn delete(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &'static str,
        delete_behavior: DeleteBehavior,
        filter: Option<Filter>,
    ) -> DbmsResult<u64>;
    fn update(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &'static str,
        patch_values: &[(ColumnDef, Value)],
        filter: Option<Filter>,
    ) -> DbmsResult<u64>;
    fn validate_insert(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &'static str,
        record_values: &[(ColumnDef, Value)],
    ) -> DbmsResult<()>;
    fn validate_update(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        table_name: &'static str,
        record_values: &[(ColumnDef, Value)],
        old_pk: Value,
    ) -> DbmsResult<()>;
    fn migrate_default(table: &str, column: &str) -> Option<Value>
       where Self: Sized;
    fn migrate_default_dyn(&self, table: &str, column: &str) -> Option<Value>;
    fn migrate_transform(
        table: &str,
        column: &str,
        old: Value,
    ) -> DbmsResult<Option<Value>>
       where Self: Sized;
    fn migrate_transform_dyn(
        &self,
        table: &str,
        column: &str,
        old: Value,
    ) -> DbmsResult<Option<Value>>;
    fn compiled_snapshots() -> Vec<TableSchemaSnapshot>
       where Self: Sized;
    fn compiled_snapshots_dyn(&self) -> Vec<TableSchemaSnapshot>;
    fn renamed_from_dyn(&self, table: &str, column: &str) -> Vec<&'static str>;

    // Provided method
    fn select_join(
        &self,
        dbms: &WasmDbmsDatabase<'_, M, A>,
        from_table: &str,
        query: Query,
    ) -> DbmsResult<Vec<Vec<(JoinColumnDef, Value)>>> { ... }
}

Provides schema-driven dynamic dispatch for database operations.

Implementations of this trait know which concrete table types exist and forward generic operations (identified by table name) to the appropriate typed methods on WasmDbmsDatabase.

This trait is typically implemented by generated code from the #[derive(DatabaseSchema)] macro.

Required Methods

fn select( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &str, query: Query, ) -> DbmsResult<Vec<Vec<(ColumnDef, Value)>>>

Performs a generic select for the given table name and query.

fn aggregate( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &str, query: Query, aggregates: &[AggregateFunction], ) -> DbmsResult<Vec<AggregatedRow>>

Performs an aggregate query for the given table name

fn referenced_tables( &self, table: &'static str, ) -> Vec<(&'static str, Vec<&'static str>)>

Returns tables and columns that reference the given table via foreign keys.

fn insert( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &'static str, record_values: &[(ColumnDef, Value)], ) -> DbmsResult<()>

Performs an insert for the given table name.

fn delete( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &'static str, delete_behavior: DeleteBehavior, filter: Option<Filter>, ) -> DbmsResult<u64>

Performs a delete for the given table name.

fn update( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &'static str, patch_values: &[(ColumnDef, Value)], filter: Option<Filter>, ) -> DbmsResult<u64>

Performs an update for the given table name.

fn validate_insert( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &'static str, record_values: &[(ColumnDef, Value)], ) -> DbmsResult<()>

Validates an insert operation.

fn validate_update( &self, dbms: &WasmDbmsDatabase<'_, M, A>, table_name: &'static str, record_values: &[(ColumnDef, Value)], old_pk: Value, ) -> DbmsResult<()>

Validates an update operation.

fn migrate_default(table: &str, column: &str) -> Option<Value>

where Self: Sized,

Returns the default value of a column for a given table, if any.

Looks up the table’s per-row Migrate::default_value hook, then falls back to the #[default] attribute compiled into ColumnDef::default. Used by the migration planner to satisfy AddColumn ops on non-nullable columns.

fn migrate_default_dyn(&self, table: &str, column: &str) -> Option<Value>

Object-safe sibling of Self::migrate_default.

The macro emits a one-line dispatch to the Sized variant so callers holding a &dyn DatabaseSchema can resolve AddColumn defaults without re-genericising on S.

fn migrate_transform( table: &str, column: &str, old: Value, ) -> DbmsResult<Option<Value>>

where Self: Sized,

Transforms a stored value when migrating a column to an incompatible type by dispatching to the table’s Migrate::transform_column hook.

fn migrate_transform_dyn( &self, table: &str, column: &str, old: Value, ) -> DbmsResult<Option<Value>>

Object-safe sibling of Self::migrate_transform.

fn compiled_snapshots() -> Vec<TableSchemaSnapshot>

where Self: Sized,

Returns the compile-time TableSchemaSnapshot for every table in the schema.

Used by drift detection (boot path) and by the migration planner to diff against the snapshots stored on disk.

fn compiled_snapshots_dyn(&self) -> Vec<TableSchemaSnapshot>

Object-safe sibling of Self::compiled_snapshots.

WasmDbmsDatabase holds a Box<dyn DatabaseSchema>, so it cannot call compiled_snapshots() directly (that method requires Self: Sized).

fn renamed_from_dyn(&self, table: &str, column: &str) -> Vec<&'static str>

Returns the compile-time renamed_from chain for column on table.

Used by the migration diff stage to detect rename operations: when a compiled column does not match any stored column by name, the diff walks this list looking for a stored column under a previous name.

Provided Methods

fn select_join( &self, dbms: &WasmDbmsDatabase<'_, M, A>, from_table: &str, query: Query, ) -> DbmsResult<Vec<Vec<(JoinColumnDef, Value)>>>

Performs a join query, returning results with column definitions that include source table names.

Implementors