feat:pg数据库适配

ruoyi-system/src/main/resources/mapper/system/ElUserExamMapper.xml

@@ -49,7 +49,6 @@
             SUM (CASE WHEN passed = 0 THEN 1 ELSE 0 END) AS wtg
         FROM
             el_user_exam u
-        ORDER BY u.create_time
     </select>
 
     <select id="selectCountExam"  resultType="com.ruoyi.system.domain.userexam.dto.response.ExamCountDTO">
@@ -62,8 +61,7 @@
         FROM
             el_user_exam u
         GROUP BY
-            exam_id
-        ORDER BY u.create_time desc LIMIT 10
+            exam_id  LIMIT 10
     </select>
     <select id="countExamMonth" resultType="java.lang.Integer" parameterType="ExamManagerDTO">