update recommender to take interest overlap into consideration

Author: aster-void

server/prisma/sql/recommend.sql

@@ -1,33 +1,28 @@
-SELECT recv.id, 
-    (SELECT COUNT(*) FROM "Enrollment" recv_enroll
-    INNER JOIN "Enrollment" req_enroll
-    ON recv_enroll."courseId" = req_enroll."courseId" 
-    WHERE recv_enroll."userId" = recv.id
-    AND req_enroll."userId" = $1)
-AS overlap FROM "User" recv
-WHERE recv.id <> $1
+SELECT
+    $1 AS senderId,
+    recv, 
+    (SELECT COUNT(1) FROM "Course" course
+        WHERE EXISTS (SELECT 1 FROM "Enrollment" e WHERE e.userId = recv.id)
+        AND EXISTS (SELECT 1 FROM "Enrollment" e WHERE e.userId = senderId)
+    ) AS course_overlap,
+    (SELECT COUNT(1) FROM "InterestSubject" subj
+        WHERE EXISTS (SELECT 1 FROM "Interest" i WHERE i.userId = recv.id)
+        AND EXISTS (SELECT 1 FROM "Interest" i WHERE i.userId = senderId)
+    ) AS interest_overlap
+FROM "User" recv
+WHERE recv.id <> senderId
 
 AND NOT EXISTS (
     SELECT 1 FROM "Relationship" rel
-    WHERE rel."sendingUserId" IN ($1, recv.id) AND rel."receivingUserId" IN ($1, recv.id)
+    WHERE rel."sendingUserId" IN (senderId, recv.id) AND rel."receivingUserId" IN (senderId, recv.id)
     AND (status = 'MATCHED' OR status = 'REJECTED')
 )
 
 AND NOT EXISTS (
     SELECT 1 FROM  "Relationship" rel_pd
-    WHERE rel_pd."sendingUserId" = $1 AND rel_pd."receivingUserId" = recv.id
+    WHERE rel_pd."sendingUserId" = senderId AND rel_pd."receivingUserId" = recv.id
     AND status = 'PENDING'
 )
 
-ORDER BY overlap DESC
+ORDER BY course_overlap + interest_overlap DESC
 LIMIT $2 OFFSET $3;
-
--- SELECT recv.id AS recv, COUNT(recv_enroll) AS overlap FROM "User" recv
--- LEFT JOIN "Relationship" rel ON (rel."sendingUserId" = recv.id AND rel."receivingUserId" = $1) OR (rel."sendingUserId" = $1 AND rel."sendingUserId" = recv.id)
--- LEFT JOIN "Enrollment" recv_enroll ON recv_enroll."userId" = recv.id
--- INNER JOIN "Course" course ON recv_enroll."courseId" = course.id
--- INNER JOIN "Enrollment" req_enroll ON req_enroll."courseId" = course.id
--- WHERE req_enroll."userId" = $1 AND recv.id <> $1
--- AND rel.status != 'MATCHED'
--- GROUP BY recv.id
--- ORDER BY overlap DESC LIMIT $2 OFFSET $3;