计算左联接并在其中使用

Question

我目前有以下sql（由typeorm生成）。

 SELECT
   "media"."permissionOwner" AS "media_permissionOwner",
   "media"."permissionGroup" AS "media_permissionGroup",
   "media"."permissionOther" AS "media_permissionOther",
   "media"."id" AS "media_id",
   "media"."filename" AS "media_filename",
   "media"."mime" AS "media_mime",
   "media"."description" AS "media_description",
   "media"."length" AS "media_length",
   (
      SELECT
         1 
      FROM
         "user" "user" 
      WHERE
         "user"."id" = $1 LIMIT 1
   )
   AS "user" 
FROM
   "media_object" "media" 
   LEFT JOIN
      "media_object_groups_group" "media_groups" 
      ON "media_groups"."mediaObjectId" = "media"."id" 
   LEFT JOIN
      "group" "groups" 
      ON "groups"."id" = "media_groups"."groupId" 
   LEFT JOIN
      "media_object_owner_user" "media_owner" 
      ON "media_owner"."mediaObjectId" = "media"."id" 
   LEFT JOIN
      "user" "owner" 
      ON "owner"."id" = "media_owner"."userId" 
WHERE
   (
      "media"."permissionGroup" >= $2 
      AND 
      COUNT("groups") = 0 -- How can I accomplish this
   )
   OR 
   (
      "media"."permissionGroup" >= $3 
      AND groups @ > user_groups
   )
   OR 
   (
      owner @ > ARRAY[user] 
      AND "media"."permissionOwner" >= $4
   )
   OR "media"."permissionOther" >= $5   -- PARAMETERS: [23,4,4,4,4]

问题是，我不能使用HAVING，因为它似乎不像WHERE那样支持这种条件创建。

我在COUNT部分使用子查询进行了尝试，但后来我无法访问子选择计数查询中的“组”别名。

我什至不确定查询的其他部分是否有效，但是首先我想解决“计数”问题。