Module read_model_store 

SQLite Read Model Store

Production-grade implementation of ReadModelStore backed by an r2d2-pooled SQLite connection. Each projection table follows the framework’s standard projection shape: (id TEXT PK, version BIGINT, data TEXT). The data column holds the full row as JSON, so this store can serve any projector without compile-time knowledge of the domain-specific columns.

Idempotency

upsert translates to

INSERT INTO {table} (id, version, data) VALUES (?, ?, ?)
ON CONFLICT(id) DO UPDATE
   SET version = excluded.version, data = excluded.data
 WHERE {table}.version < excluded.version

That gate makes replay-from-zero deterministic and tolerates at-least-once delivery: applying an older event twice, or out-of-order, never regresses state.

Queries

find_by uses json_extract(data, '$.{field}') to reach into the blob. Columns commonly queried (e.g. email) get expression indexes in the migration that creates the table.

Boundaries

The store does not create tables — DDL lives in migrations/. That keeps the production write path away from connection-time mutations and lets diesel migration run control schema evolution.

Structs

SqliteReadModelStore

SQLite implementation of ReadModelStore.