mybatis 如何通过resultMap 返回long

mybatis resultMap 返回long

mybatis long 类型返回为null报异常

Mapper method 'com.mpn.dao.TWeatherMapper.avgWeatherTemperature attempted to return null from a method with a primitive return type (long).

        SELECT IFNULL(AVG(WeatherTemperature),0) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  
  
   
        SELECT SUM(WeatherTemperature) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  
  
   
        SELECT IFNULL(AVG(WeatherHumidity),0) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  

由于返回为空long中没有此类型所以抛异常，改为

   
        SELECT IFNULL(AVG(WeatherTemperature),0) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  
  
   
        SELECT IFNULL(SUM(WeatherTemperature),0) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  
  
   
        SELECT IFNULL(AVG(WeatherHumidity),0) AS OrderAverage FROM t_weather WHERE WeatherDate= #{date,jdbcType=VARCHAR};
  

用IFNULL来进行判断！

以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。