SQLite snapshot support

Use this matrix to decide which SQLite schema facts Qubu v1 can serialize and which combinations must be diagnosed before a snapshot is written.

Import the adapter from the SQLite snapshot subpath:

import { createSchemaSnapshot, tryCreateSchemaSnapshot } from "qubu/snapshot/sqlite"

const snapshot = createSchemaSnapshot(appSchema)
const result = tryCreateSchemaSnapshot(appSchema)

The snapshot dialect is sqlite, the same name used by Qubu's query dialect. This shared name is intentional: SQLite does not need a second metadata identity to distinguish it from the query renderer. A dialect-tagged unsafeSchemaSql('sqlite', sql) expression belongs to this adapter.

Support matrix

Schema fact	SQLite v1 behavior
Portable storage	Maps integer, boolean, and bigint to INTEGER; text, date, timestamp, uuid, and json to TEXT; numeric to NUMERIC; and binary to BLOB. The snapshot also records SQLite's derived affinity.
Native storage	Preserves a non-empty declaration tagged sqlite exactly and records its affinity using SQLite's ordered declared-type rules. Other dialect tags fail.
Literals	Encodes NULL, finite numbers, strings, bigint, and booleans as parameter-free SQL. Boolean literals use 1 and 0; strings retain SQL escaping.
Defaults	Canonical literals, branded deterministic expressions, and explicit external behavior are retained. Default expressions cannot reference columns or parameters.
Generated columns	Both stored and virtual modes are retained. Generated columns cannot be used in a SQLite PRIMARY KEY; expressions still pass through the shared deterministic schema-expression boundary.
Identity and rowids	Identity columns require INTEGER affinity and a single-column PRIMARY KEY. Set identityColumn(..., { dialect: { dialect: 'sqlite', autoIncrement: true } }) only with an exact INTEGER declaration to represent SQLite AUTOINCREMENT.
Keys and checks	Primary keys, strict unique keys, ordinary unique constraints, foreign keys, and checks retain logical and physical names. Constraint DEFERRABLE timing is diagnosed except on foreign keys.
Foreign keys	Standard update/delete actions and MATCH SIMPLE are retained. MATCH FULL and MATCH PARTIAL are diagnosed because the v1 adapter does not claim SQLite support for them.
Nullable uniqueness	nulls: 'distinct' is supported. nulls: 'not-distinct' is diagnosed because SQLite's ordinary UNIQUE semantics distinguish NULLs.
Indexes	Ordered terms, expressions, uniqueness, predicates for partial indexes, and candidate-key evidence are retained. Included columns are diagnosed as unsupported. The typed SQLite index extension is encoded under dialect.
Namespaces	An optional unqualified namespace is retained; Qubu does not attach or inspect SQLite databases.

Capability checks run before common traversal. Use the non-throwing form when a schema may include a feature that depends on a SQLite version or table shape:

const result = tryCreateSchemaSnapshot(appSchema)
if (!result.ok) {
  for (const issue of result.diagnostics) {
    console.error(issue.path.join("."), issue.code, issue.message)
  }
}

The adapter does not connect to SQLite, inspect sqlite_master, or emit DDL. It produces deterministic data for the strict qubu/snapshot decoder. The package-wide ownership map shows the separate schema and application boundaries.