fix: update sql solution to lc problem: No.0602 (#2703)

Author: Professorx911

solution/0600-0699/0602.Friend Requests II Who Has the Most Friends/README.md

@@ -73,10 +73,10 @@ RequestAccepted 表：
 WITH
     T AS (
         SELECT requester_id, accepter_id FROM RequestAccepted
-        UNION
+        UNION ALL
         SELECT accepter_id, requester_id FROM RequestAccepted
     )
-SELECT requester_id AS id, COUNT(accepter_id) AS num
+SELECT requester_id AS id, COUNT(1) AS num
 FROM T
 GROUP BY 1
 ORDER BY 2 DESC

solution/0600-0699/0602.Friend Requests II Who Has the Most Friends/README_EN.md

@@ -66,10 +66,10 @@ The person with id 3 is a friend of people 1, 2, and 4, so he has three friends
 WITH
     T AS (
         SELECT requester_id, accepter_id FROM RequestAccepted
-        UNION
+        UNION ALL
         SELECT accepter_id, requester_id FROM RequestAccepted
     )
-SELECT requester_id AS id, COUNT(accepter_id) AS num
+SELECT requester_id AS id, COUNT(1) AS num
 FROM T
 GROUP BY 1
 ORDER BY 2 DESC

solution/0600-0699/0602.Friend Requests II Who Has the Most Friends/Solution.sql

@@ -2,10 +2,10 @@
 WITH
     T AS (
         SELECT requester_id, accepter_id FROM RequestAccepted
-        UNION
+        UNION ALL
         SELECT accepter_id, requester_id FROM RequestAccepted
     )
-SELECT requester_id AS id, COUNT(accepter_id) AS num
+SELECT requester_id AS id, COUNT(1) AS num
 FROM T
 GROUP BY 1
 ORDER BY 2 DESC