用户收藏sql优化，接口增加缓存

src/main/resources/mapper/course/CourseCollectDao.xml

@@ -10,44 +10,23 @@
         c.*,
         d.course_details_name AS courseDetailsName,
         d.course_details_id AS courseDetailsId,
-        cd.course_details_count AS courseDetailsCount
+        COUNT(d.course_details_id) AS courseDetailsCount
         FROM
         course_collect u
-        LEFT JOIN course c ON u.course_id = c.course_id
-        LEFT JOIN (
-        SELECT
-        cc.course_id,
-        cc.user_id,
-        d.course_details_name,
-        d.course_details_id
-        FROM
-        course_collect cc
-        LEFT JOIN course_details d ON cc.course_details_id = d.course_details_id
-        WHERE
-        cc.classify = 3
-        AND cc.user_id = #{userId}
-        ORDER BY
-        cc.update_time DESC
-        ) AS d ON u.course_id = d.course_id
-        LEFT JOIN (
-        SELECT
-        d.course_id,
-        COUNT(*) AS course_details_count
-        FROM
-        course_details d
-        GROUP BY
-        d.course_id
-        ) AS cd ON c.course_id = cd.course_id
+        LEFT JOIN
+        course c ON u.course_id = c.course_id
+        LEFT JOIN
+        course_details d ON u.course_details_id = d.course_details_id
+        LEFT JOIN
+        course_collect cc ON u.course_id = cc.course_id AND cc.user_id = #{userId} AND cc.classify = 3
         WHERE
         u.user_id = #{userId}
-        AND c.course_id IS NOT NULL
         AND u.classify = #{classify}
+        AND c.course_id IS NOT NULL
         GROUP BY
-        u.course_id
+        u.course_id, c.course_id, d.course_details_name, d.course_details_id
         ORDER BY
-        produceEndTime DESC
-
-
+        produceEndTime DESC;
 
         <!--       SELECT
                    MAX( u.update_time ) AS produceEndTime,