when query a dimension having null value with not equal or not in get wrong result

hi,all: when I query with this sql : SELECT NATION, DATES, IS_JOIN ,SUM(REC_AMT) AS sum_REC_AMT FROM GJST.SH_FETCH_SALE_BASE_FACT_ALL_NEW WHERE NATION IN ('控股') AND DATES IN ('2020-02-11') GROUP BY NATION, DATES, IS_JOIN; I can see there is a null value in

回复：when query a dimension having null value with not equal or not in get wrong result

在写SQL 条件语句是经常用到 不等于‘<>’的筛选条件，此时要注意此条件会将字段为null的数据也当做满足不等于的条件而将数据筛选掉。 -- 发件人：lk_hadoop 发送时间：2020年2月12日(星期三) 19:15 收件人：user ; dev 主　题：when query a dimension having null value with not equal or not in get wrong result hi,all: