Apache Superset SQLLab中PostgreSQL <<=网络地址运算符兼容问题咨询

部署新的Apache Superset实例后，通过SQLLab对PostgreSQL数据库执行SQL查询基本正常，但使用PostgreSQL表示“包含于或等于”的网络地址运算符<<=时出现异常。

对应的SQL语句如下：

WITH subnets AS (
SELECT UNNEST(networks) AS subnet,
       network_owner,
       owner_country,
       provider_country,
       registrar
  FROM network_data
)
   SELECT network_owner,
          owner_country,
          provider_country,
          registrar,
          subnet,
          (2 ^ (32 - MASKLEN(subnet)) - 2) AS subnet_size,
          (
              SELECT COUNT(DISTINCT(q.ip_address))
                FROM request q
               WHERE q.ip_address <<= subnet
          ) AS num_logged,
          u.timestamp AS blocked_timestamp
     FROM subnets
LEFT JOIN ufw_blocked u ON subnet = u.blocked_address_space
 ORDER BY network_owner, subnet

该语句在pgAdmin4中可正常运行，但Superset的SQLLab将<<=误判为“小于等于”运算符，返回以下错误：

Unable to parse SQL:
Error parsing near '<=' at line 18:37
WHERE q.ip_address <<= subnet
                     ^

DB Engine Error: This database does not allow for DDL/DML, and the query could not be parsed to confirm it is a read-only query. Please contact your administrator for more assistance
This may be triggered by:
Issue 1022 - Database does not allow data manipulation

PostgreSQL的<<=网络地址运算符有两种等效替代写法，可避开Superset解析器的误判：

• 使用等效函数inet_contained_or_equal(ip_column, subnet_column)，这是<<=运算符的官方函数形式
• 拆解逻辑为q.ip_address << subnet OR q.ip_address = subnet（<<表示“包含于”，加上等于判断即等价于<<=）

修改后的子查询示例（使用函数写法）：

(
    SELECT COUNT(DISTINCT(q.ip_address))
      FROM request q
     WHERE inet_contained_or_equal(q.ip_address, subnet)
) AS num_logged

两种写法都能实现和原运算符完全一致的逻辑，且能被Superset的SQL解析器正确识别，避免误判为DDL/DML操作。

内容的提问来源于stack exchange，提问作者pytinkerer