sql数字不为null

src/main/resources/mapper/digitalwater/WaterBigDataMapper.xml

@@ -220,7 +220,7 @@
             count( b.id ) DESC
     </select>
     <select id="selectCenterdataTHydraulicRiverList" resultType="java.util.Map">
-        select a.id,a.name,a.riverway_length as riverwayLength,a.basin_area as basinArea,group_concat(b.hamlet_id) hamlet from centerdata_t_hydraulic_river a
+        select a.id,a.name,ifnull(a.riverway_length,0) as riverwayLength,ifnull(a.basin_area,0) as basinArea,group_concat(b.hamlet_id) hamlet from centerdata_t_hydraulic_river a
         left join centerdata_t_hydraulic_river_bind_hamlet b ON b.river_id = a.id
         left join ${database_system}.sys_dept d on d.dept_id = a.dept_id
         <where>