fix老师详情头象

cooleshow-user/user-biz/src/main/resources/config/mybatis/TeacherMapper.xml

@@ -227,7 +227,7 @@
         SELECT
         <include refid="baseColumns"/>,
         if(u.lock_flag_ = 0 and t.lock_flag_ = 0,0,1) as lockFlag,
-        u.avatar_ as avatar,
+        if(t.avatar_ = '' OR t.avatar_ = NULL, u.avatar_, t.avatar_) as avatar,
         u.username_ as username,
         u.gender_ as `gender`,
         u.birthdate_ as birthdate,