source/core/migration/auto/schema_diff library

The pure, synchronous heart of auto-migration: compare a declared DatumSchema against a store's observed SchemaShape and produce the ColumnOperations that reconcile them.

Classes

SchemaChange

One reconciliation step the differ decided on.

SchemaColumnAdded

A declared field is missing from the store and will be added (backfilled with its default / null).

SchemaColumnRemoved

A stored column not present in the declaration will be dropped (only when autoMigrateDropColumns is on).

SchemaColumnRenamed

A stored column will be renamed to a declared field (via renamedFrom:).

SchemaRenameOperation

A rename that never clobbers: on the map path the value moves only when the target key is absent (a partially-migrated row keeps its newer value); on the SQL path it emits ALTER TABLE … RENAME COLUMN through the SqlConvertibleOperation hook.

Constants

kReservedColumnNames → const Set<String>

Column names auto-migration never adds, renames, or drops: the sync core fields plus anything __-prefixed (engine-internal, e.g. __typename).

Functions

diffSchema<E extends DatumEntityInterface>({required DatumSchema<E> schema, required SchemaShape actual, required bool dropRemovedColumns, required bool sqlPath, SqlDialect dialect = SqlDialect.sqlite}) → SchemaDiffResult

Diffs schema against the observed actual shape.

Typedefs

SchemaDiffResult = ({List<SchemaChange> changes, List<ColumnOperation> operations, List<String> warnings})

The differ's output: the decided changes, the operations that execute them (fed into the existing map / SQL migration machinery), and human-readable warnings for everything noticed but deliberately not touched.