如何在laravel 5.5中加入子查询？

Question

I have a table that has two relationship with other table but the same field.

For example:

first_user_in_comment_id & last_user_in_comment_id

so these fields has relation with the name user name_user

My laravel version is 5.5

 $conseguirTabla = DB::table('ALUMNOS_HISTORIAL_COMENTARIOS')   
        ->JOIN('CICLOS_ESCOLARES','CICLOS_ESCOLARES.ID','=','ALUMNOS_HISTORIAL_COMENTARIOS.CICLO_ID')
        ->JOIN('USUARIOS','USUARIOS.ID','=','ALUMNOS_HISTORIAL_COMENTARIOS.USUARIO_ID')
       ->JOIN('USUARIOS','USUARIOS.ID','=','ALUMNOS_HISTORIAL_COMENTARIOS.USUARIO_MODIFICACION_ID')
            ->SELECT('USUARIOS.NOMBRE AS NOMBRE', 
                    'CICLOS_ESCOLARES.CICLO_ESCOLAR AS CICLO_ESCOLAR',
                    'ALUMNOS_HISTORIAL_COMENTARIOS.FECHA_COMENTARIO AS FECHA_COMENTARIO',
                    'ALUMNOS_HISTORIAL_COMENTARIOS.COMENTARIO AS COMENTARIO',
                    'ALUMNOS_HISTORIAL_COMENTARIOS.USUARIO_MODIFICACION_ID AS MODIFICACION'
            )   

            ->WHERE('ALUMNO_ID',$idAlumno)         
            ->get();

Answer 1

You can use DB::raw for example:

       ->JOIN(\DB::raw('USUARIOS as x'),'x.ID','=','ALUMNOS_HISTORIAL_COMENTARIOS.USUARIO_MODIFICACION_ID')
       ->JOIN(\DB::raw('(select * from USUARIOS) as y'),'y.ID','=','ALUMNOS_HISTORIAL_COMENTARIOS.USUARIO_MODIFICACION_ID')