Arango AQL查询NOT IN

Question

我正在创建一个类似Facebook的网站，我想为在同一学校学习的用户推荐朋友，但还不是朋友。

我已经尝试做这个AQL查询，但似乎有一个语法问题。

返回的错误代码是

语法错误, "user._key不在(for friend in...) "附近的意外标识符在3: 3位置(解析时)

for user in users
  filter user._key != "myself"
    user._key not in (for user in 1..1 outbound "users/myself" friendship return user) 
      user._key not in (for user in 1..1 outbound "users/myself" schoolStudies return user)
    return user

Answer 1

如果你想应用几个过滤标准，你必须通过逻辑组合他们 AND (或其 && 操作者)

FOR user IN users
  FILTER user._key != "myself" AND
    user._key not in (for user in 1..1 outbound "users/myself" friendship return user) AND
    user._key not in (for user in 1..1 outbound "users/myself" schoolStudies return user)
  RETURN user

或者你可以使用单独的FILTER子句

FOR user IN users
  FILTER user._key != "myself"
  FILTER user._key not in (for user in 1..1 outbound "users/myself" friendship return user)
  FILTER user._key not in (for user in 1..1 outbound "users/myself" schoolStudies return user)
  RETURN user