fix some api

Change-Id: I7179a115c9ed3e7d3473c1761df1bb4f2bf3711e
diff --git a/src/main/java/com/example/g8backend/mapper/UserMapper.java b/src/main/java/com/example/g8backend/mapper/UserMapper.java
index 98e6c67..f913b0f 100644
--- a/src/main/java/com/example/g8backend/mapper/UserMapper.java
+++ b/src/main/java/com/example/g8backend/mapper/UserMapper.java
@@ -18,4 +18,17 @@
 
     @Update("UPDATE users SET user_level = #{userLevel} WHERE user_id = #{userId}")
     int updateUserLevel(@Param("userId") Long userId, @Param("userLevel") String userLevel);
+
+    @Select("SELECT COUNT(*) FROM user_follows WHERE followed_id = #{userId}")
+    int countFollowings(Long userId);
+
+    @Select("SELECT COUNT(*) FROM user_follows WHERE follower_id = #{userId}")
+    int countFollowers(Long userId);
+
+    @Select("SELECT COUNT(*) FROM user_follows " +
+            "WHERE follower_id = #{currentUserId} AND followed_id = #{targetUserId}")
+    int existsFollowRelationship(
+            @Param("currentUserId") Long currentUserId,
+            @Param("targetUserId") Long targetUserId
+    );
 }