Method DiffSchema

backend/api/v1/database_service.go:684–716

DiffSchema diff the database schema.

(ctx context.Context, req *connect.Request[v1pb.DiffSchemaRequest])

// DiffSchema diff the database schema.
func (s *DatabaseService) DiffSchema(ctx context.Context, req *connect.Request[v1pb.DiffSchemaRequest]) (*connect.Response[v1pb.DiffSchemaResponse], error) {
	engine, err := s.getParserEngine(ctx, req.Msg)
	if err != nil {
		return nil, connect.NewError(connect.CodeInternal, errors.Wrapf(err, "failed to get parser engine"))
	}

	// PG/CockroachDB raw schema text still needs the omni SDL diff path. Metadata
	// targets such as changelogs use schema.DiffMigration's metadata path.
	if shouldDiffSchemaViaSDL(engine, req.Msg) {
		migrationSQL, err := s.diffSchemaViaSDL(ctx, req.Msg, engine)
		if err != nil {
			return nil, connect.NewError(connect.CodeInternal, errors.Wrapf(err, "failed to compute schema diff"))
		}
		return connect.NewResponse(&v1pb.DiffSchemaResponse{Diff: migrationSQL}), nil
	}

	// Metadata-backed diff path. PostgreSQL/CockroachDB changelog targets use
	// their registered metadata migration here, while other engines keep the
	// existing metadata parser/generator behavior.
	sourceDBSchema, err := s.getSourceDBMetadata(ctx, req.Msg)
	if err != nil {
		return nil, connect.NewError(connect.CodeInternal, errors.Wrapf(err, "failed to get source schema"))
	}
	targetDBSchema, err := s.getTargetDBMetadata(ctx, req.Msg)
	if err != nil {
		return nil, connect.NewError(connect.CodeInternal, errors.Wrapf(err, "failed to get target schema"))
	}
	migrationSQL, err := schema.DiffMigration(engine, sourceDBSchema, targetDBSchema)
	if err != nil {
		return nil, connect.NewError(connect.CodeInternal, errors.Wrapf(err, "failed to compute schema diff"))
	}
	return connect.NewResponse(&v1pb.DiffSchemaResponse{Diff: migrationSQL}), nil
}

func shouldDiffSchemaViaSDL(engine storepb.Engine, req *v1pb.DiffSchemaRequest) bool {
	if engine != storepb.Engine_POSTGRES && engine != storepb.Engine_COCKROACHDB {