distinct去重
1、单字段去重 select distinct aly_layer from t_aly_il_result

2、多字段去重 select distinct aly_layer,CREATE_TIME from t_aly_il_result

3、对去重字段进行统计 select count(distinct aly_layer) from t_aly_il_result

学习时的痛苦是暂时的,未学到的痛苦是终生的
1、单字段去重 select distinct aly_layer from t_aly_il_result

2、多字段去重 select distinct aly_layer,CREATE_TIME from t_aly_il_result

3、对去重字段进行统计 select count(distinct aly_layer) from t_aly_il_result
