在这种情况下，您试图在对两个子查询应用EXCEPT子句后聚合它们的结果。要实现这一点，可以先应用EXCEPT，然后使用公共表表达式（CTE）执行聚合。以下是您的更新查询：

WITH cte AS (
    SELECT utc_offset, is_dst,
           ltrim(
               trim(string_agg(distinct (CASE WHEN abbrev NOT LIKE '+%' AND abbrev NOT LIKE '-%' AND abbrev != name THEN abbrev ELSE '' END), ' ')) ||
               ' ' || string_agg(name, ', ' ORDER BY name)
           ) AS agg_column
    FROM pg_timezone_names
    WHERE name NOT LIKE 'posix/%'
      AND name NOT LIKE 'Etc/%'
      AND (lower(abbrev) <> abbrev)
      AND name NOT IN ('HST', 'Factory', 'GMT', 'GMT+0', 'GMT-0', 'GMT0', 'localtime', 'UCT', 'Universal', 'UTC', 'PST8PDT', 'ROK', 'W-SU', 'MST', 'CST6CDT')
    GROUP BY utc_offset, is_dst
)
SELECT utc_offset, is_dst, agg_column
FROM cte
EXCEPT
SELECT n.utc_offset, n.is_dst, a.agg_column
FROM pg_timezone_names n 
JOIN pg_timezone_abbrevs a ON a.abbrev = n.name
WHERE n.utc_offset <> a.utc_offset
ORDER BY utc_offset, is_dst;

希望它能起作用：）

您遇到的错误是由EXCEPT子句引起的，该子句组合了两个查询的结果。使用EXCEPT时，两个查询的列名和数据类型必须匹配。在您的示例中，第一个查询选择特定的列（utc_offset、is_dst和一个连接字符串），而第二个查询使用n.* 和a.* 从pg_timezone_names和pg_timezone_focus vs表中选择所有列。列选择中的这种不匹配导致了错误。若要解决此问题，请更新查询，使EXCEPT语句的两个部分中的SELECT子句具有相同的列名和数据类型。在EXCEPT子句的两个部分中，您可以专门选择所需的列。以下是如何修改查询：

SELECT utc_offset, is_dst,
       ltrim(
               trim(string_agg(distinct (CASE WHEN abbrev NOT LIKE '+%' AND abbrev NOT LIKE '-%' AND abbrev != name THEN abbrev ELSE '' END), ' ')) ||
               ' ' || string_agg(name, ', ' ORDER BY name)
       )
FROM pg_timezone_names
WHERE name NOT LIKE 'posix/%'
  AND name NOT LIKE 'Etc/%'
  AND (lower(abbrev) <> abbrev)
  AND name NOT IN ('HST', 'Factory', 'GMT', 'GMT+0', 'GMT-0', 'GMT0', 'localtime', 'UCT', 'Universal', 'UTC', 'PST8PDT', 'ROK', 'W-SU', 'MST', 'CST6CDT')
EXCEPT
SELECT n.utc_offset, n.is_dst,
       ltrim(
               trim(string_agg(distinct (CASE WHEN a.abbrev NOT LIKE '+%' AND a.abbrev NOT LIKE '-%' AND a.abbrev != n.name THEN a.abbrev ELSE '' END), ' ')) ||
               ' ' || string_agg(n.name, ', ' ORDER BY n.name)
       )
FROM   pg_timezone_names n 
JOIN   pg_timezone_abbrevs a ON  a.abbrev = n.name
WHERE  n.utc_offset <> a.utc_offset
GROUP BY n.utc_offset, n.is_dst
ORDER BY n.utc_offset, n.is_dst;

希望有帮助。