【Impala】根据当前日期取去年、今年、上月、日期差

--去年
SUBSTR(REGEXP_REPLACE(CAST(YEARS_ADD(NOW(), 1) AS STRING) ,'-',''),1,4) AS LAST_YEAR

--今年
SUBSTR(REGEXP_REPLACE(CAST(NOW() AS STRING),'-',''),1,4) AS THIS YEAR

--上月
SUBSTR(REGEXP_REPLACE(CAST(MONTHS_ADD(NOW(), 1) AS STRING) ,'-',''),1,4) AS LAST_YEAR

--日期差
DATEDIFF(FROM_UNIXTIME(UNIX_TIMESTAMP(END_DATE,'YYYYMMDD'),'YYYY-MM-DD'),--将end_date字段转为时间戳，再从时间戳转为日期格式(下同)
                  FROM_UNIXTIME(UNIX_TIMESTAMP(RECEIVE_DATE,'YYYYMMDD'),'YYYY-MM-DD'))  AS DAYS