Function streamFromVirtual

packages/sql/src/AbstractSqlDriver.ts:380–425

(
    entityName: EntityName<T>,
    where: FilterQuery<T>,
    options: StreamOptions<T, any>,
  )

  }

  protected async *streamFromVirtual<T extends object>(
    entityName: EntityName<T>,
    where: FilterQuery<T>,
    options: StreamOptions<T, any>,
  ): AsyncIterableIterator<EntityData<T>> {
    const meta = this.metadata.get<T>(entityName);

    /* v8 ignore next */
    if (!meta.expression) {
      return;
    }

    if (typeof meta.expression === 'string') {
      yield* this.wrapVirtualExpressionInSubqueryStream(meta, meta.expression, where, options, QueryType.SELECT);
      return;
    }

    const em = this.createEntityManager();
    em.setTransactionContext(options.ctx);
    const res = meta.expression(em, where as any, options as FindOptions<T, any, any, any>, true);

    if (typeof res === 'string') {
      yield* this.wrapVirtualExpressionInSubqueryStream(meta, res, where, options, QueryType.SELECT);
      return;
    }

    if (res instanceof QueryBuilder) {
      yield* this.wrapVirtualExpressionInSubqueryStream(
        meta,
        res.getFormattedQuery(),
        where,
        options,
        QueryType.SELECT,
      );
      return;
    }

    if (isRaw(res)) {
      const expr = this.platform.formatQuery(res.sql, res.params);
      yield* this.wrapVirtualExpressionInSubqueryStream(meta, expr, where, options, QueryType.SELECT);
      return;
    }

    /* v8 ignore next */
    yield* res as EntityData<T>[];
  }

  protected async wrapVirtualExpressionInSubquery<T extends object>(
    meta: EntityMetadata<T>,