选择存在子关系（子查询）作为1/0列

Question

I am trying to get the result of a subquery as a column that is 1 or 0 based on its relationship.

This is a heavy report as well, so I want to avoid extra queries after the initial query.

DB::raw('EXISTS(
   SELECT 1 
   FROM issues 
   WHERE time.id = issues.parent_id 
      AND parent_type = \'' . TimeRecord::class . '\' 
      AND deleted_at IS NULL
   ) AS flagged')

The rest of the query works, and even with this still works (just always is 0 even for rows that should be 1.

I have not found any instance of EXISTS used like this, but I have not found any alternative used as a column.

Answer 1

Have you tried COUNT ?

SELECT COUNT(*)
FROM issues 
WHERE time.id = issues.parent_id 
   AND parent_type = \'' . TimeRecord::class . '\' 
   AND deleted_at IS NULL