首页查询优化

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

@@ -39,7 +39,7 @@
         c.dy_show as dyShow,
         c.sort,
         round(10000*rand(),0) as goodNum,
-        d.courseDetailsCount,
+        ifnull(d.courseDetailsCount,0) as courseDetailsCount,
         null AS courseDetailsName,
         null AS courseDetailsId,
         round(10000*rand(),0) as weekGoodNum,
@@ -139,7 +139,7 @@
         c.course_type as courseType,
         c.banner_id as bannerId,
         b.name as bannerName,
-        d.viewCounts,
+        ifnull(d.viewCounts,0) as viewCounts,
         c.dy_img_id as dyImgId,
         c.dy_course_id as dyCourseId,
         c.dy_status as dyStatus,
@@ -170,10 +170,10 @@
         c.`wx_course_status` as wxCourseStatus,
         t.dyUrlStatus,
         o.payMoney,
-        d.goodNum,
-        d.courseDetailsCount,
+        ifnull(d.goodNum,0) as goodNum,
+        ifnull(d.courseDetailsCount) as courseDetailsCount,
         0 as weekGoodNum,
-        tt.isRecommend
+        ifnull(tt.isRecommend,0) as isRecommend
         FROM
         course AS c
         LEFT JOIN course_classification AS cc ON c.classify_id = cc.classification_id

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

@@ -4,8 +4,9 @@
 
     <!--查找指定短剧的目录  按照顺序数字升序-->
     <select id="findByCourseId" resultType="com.sqx.modules.course.entity.CourseDetails">
-        select c.*,
-               cc.isGood
+        select
+            c.*,
+            ifnull(cc.isGood,0) as isGood
         from course_details c
         left join (select course_details_id,count(*) isGood from course_collect where user_id=#{userId} and classify=2 group by course_details_id) cc on c.course_details_id = c.course_details_id
         where c.course_id=#{id}  order by c.sort asc
@@ -37,7 +38,7 @@
                c.advertising,
                c.view_count as viewCount,
                c.play_complete_count as playCompleteCount,
-               cc.isGood
+               ifnull(cc.isGood,0) as isGood
         from course_details c
         left join (select course_details_id,count(*) as isGood from course_collect where user_id=#{userId} and classify=2 group by course_details_id) cc on cc.course_details_id = c.course_details_id
         where c.course_id=#{id}  order by c.sort asc