如何使用 eloquent 在内部进行左连接的 select 子查询？

Question

I'm very new to Laravel, how can I make this query in Laravel using Eloquent model:

SELECT
(
  SELECT departments.deptname FROM school.counts
  LEFT JOIN reference.departments
  ON counts.departmentcode = department.departmentcode
  WHERE counts.countid = a.countsid
) AS departmentDesc
FROM school.subjecthdr a
LEFT JOIN school.subjectdtls b
ON a.subjectid = b.subjectid;

I don't wish to use raw queries, is there any way? I still appreciate raw query suggestions if there's any.

Answer 1

I think you still need some raw queries.

$dept_desc = \DB::table('school.counts')
->leftjoin('reference.departments', 'counts.departmentcode', '=', 'departments.departmentcode')
->whereRaw('counts.countid = a.countsid')
->selectRaw('departments.deptname');


\DB::table('school.subjecthdr AS a')
->leftjoin('subjectdtls AS b', 'a.subjectid', '=', 'b.subjectid')
->selectRaw('(' . $dept_desc->toSql() . ') AS departmentDesc')
->get();

PS: I think you leftjoin subjectdtls b but it seems you don't need it.

And you are using not only one database, if you want to use Eloquent\Builder , you need to do something like this: How to use multiple databases in Laravel