使用更优雅的方式来做同样的事情：

const posts = await connection
  .getRepository(Post)
  .createQueryBuilder("post")
  .where(qb => {
    const subQuery = qb
      .subQuery()
      .select("user.name")
      .from(User, "user")
      .where("user.registered = :registered")
      .getQuery();
    return "post.title IN " + subQuery;
  .setParameter("registered", true)
  .getMany();

你可以在FROM中创建子查询，如下所示：

const userQb = await connection
  .getRepository(User)
  .createQueryBuilder("user")
  .select("user.name", "name")
  .where("user.registered = :registered", { registered: true });
const posts = await connection
  .createQueryBuilder()
  .select("user.name", "name")
  .getRawMany();

如果想添加一个子查询做为”second from”，请使用addFrom。

const posts = await connection
  .createQueryBuilder()
  .select("post.id", "id")
  .addSelect(subQuery => {
    return subQuery
      .select("user.name", "name")
      .from(User, "user")
      .limit(1);
  }, "name")