hive 实现将多行记录合并成一行:concat_ws,collect_set,collect_list

数据表的记录如下

5112 960024
5112 960025
5112 960026
5112 960027
5112 960028
5113 960043
5113 960044
5113 960045
5113 960046

select product_id, concat_ws('_',collect_set(promotion_id)) as promotion_ids from product_promotion group by product_id

执行结果：

1. 5112 960024_960025_960026_960027_960028

2. 5113 960043_960044_960045_960046

3. Time taken: 3.116 seconds

collect_list:  合成数值, 但是有重复

collect_set: 合成数组,但是已去重