网管课导出fix

mec-biz/src/main/resources/config/mybatis/PracticeGroupMapper.xml

@@ -510,7 +510,7 @@
         su.username_ student_name_,
         o.name_ organ_name_,
         MAX(pg.courses_expire_date_) expire_date_,
-        CASE WHEN type_='FREE' THEN 0 ELSE 1 END buy_practice_
+        CASE WHEN MAX(pg.buy_months_) IS NULL THEN 0 ELSE 1 END buy_practice_
         FROM practice_group pg
         LEFT JOIN organization o on o.id_ = pg.organ_id_
         LEFT JOIN sys_user su ON su.id_ = pg.student_id_