feat(ems): 添加查询指定表最新N条记录功能并优化数据字典查询

- 在 RecordIotenvInstantMapper 中添加 selectLatestRecordsFromTable 方法
- 在 RecordIotenvInstantMapper.xml 中实现该方法的 SQL 语句
- 在 RuoYiApplication 中启用定时任务调度
- 优化 SysDictTypeMapper.xml 中的字典类型查询 SQL，top(1)是SQL server独有的，现在是TiDB（兼容MySQL）

os-admin/src/main/java/com/os/RuoYiApplication.java

@@ -3,6 +3,7 @@ package com.os;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
+import org.springframework.scheduling.annotation.EnableScheduling;
 
 /**
  * 启动程序
@@ -10,6 +11,7 @@ import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
  * @author ruoyi
  */
 @SpringBootApplication(exclude = { DataSourceAutoConfiguration.class })
+@EnableScheduling
 public class RuoYiApplication
 {
     public static void main(String[] args)

os-ems/src/main/java/com/os/ems/record/mapper/RecordIotenvInstantMapper.java

@@ -115,4 +115,13 @@ public interface RecordIotenvInstantMapper
      */
     int countFromTables(@Param("tableNames") List<String> tableNames, @Param("recordIotenvInstant") RecordIotenvInstant recordIotenvInstant);
 
+    /**
+     * 从指定表查询最新的N条记录
+     * 
+     * @param tableName 表名
+     * @param limit 限制条数
+     * @return 记录列表
+     */
+    public List<RecordIotenvInstant> selectLatestRecordsFromTable(@Param("tableName") String tableName, 
+                                                                   @Param("limit") int limit);
 }

os-ems/src/main/resources/mapper/ems/record/RecordIotenvInstantMapper.xml

@@ -296,4 +296,14 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
     ) AS total_count
 </select>
 
+    <!-- 从指定表查询最新的N条记录 -->
+    <select id="selectLatestRecordsFromTable" resultMap="RecordIotenvInstantResult">
+        SELECT objid, monitorId, temperature, humidity, illuminance, noise, concentration,
+               vibration_speed, vibration_displacement, vibration_acceleration, vibration_temp,
+               collectTime, recodeTime
+        FROM ${tableName}
+        ORDER BY objid DESC
+        LIMIT #{limit}
+    </select>
+
 </mapper>

os-system/src/main/resources/mapper/system/SysDictTypeMapper.xml

@@ -58,9 +58,10 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 	</select>
 	
 	<select id="checkDictTypeUnique" parameterType="String" resultMap="SysDictTypeResult">
-		select top(1) dict_id, dict_name, dict_type, status, create_by, create_time, remark
+		select dict_id, dict_name, dict_type, status, create_by, create_time, remark
 		from sys_dict_type
 		where dict_type = #{dictType}
+		LIMIT 1
 	</select>
 	
 	<delete id="deleteDictTypeById" parameterType="Long">