添加平均值求法

src/main/java/com/njcn/influx/query/InfluxQueryWrapper.java

@@ -284,6 +284,19 @@ public class InfluxQueryWrapper {
         selectColumns.add(selectFragment);
         return this;
     }
+    public InfluxQueryWrapper mean(String columnName,String resultName) {
+        String selectFragment = InfluxDbSqlConstant.AVG +
+                InfluxDbSqlConstant.LBK +
+                InfluxDbSqlConstant.DQM +
+                columnName +
+                InfluxDbSqlConstant.DQM +
+                InfluxDbSqlConstant.RBK +
+                InfluxDbSqlConstant.AS +
+                resultName +
+                StrPool.C_SPACE;
+        selectColumns.add(selectFragment);
+        return this;
+    }
 
     /***
      * 批量获取指定字段平均值