如果有一种字段a,b为下面这种
event_id ---1,3,4,6
user_id ---2,8,9,7
希望变成
| event_id | 1 |
| event_id | 3 |
| event_id | 4 |
| event_id | 6 |
| user_id | 2 |
| user_id | 8 |
| user_id | 9 |
| user_id | 7 |
hive 中查询sql 使用关键字 LATERAL VIEW
select event_id, col from table LATERAL VIEW explode(split(user_id,",")) t AS col;
presto 中查询获取关键字为 CROSS JOIN UNNEST
SELECT id
FROM v_event_0
CROSS JOIN UNNEST(split("event_id",',')) AS t (id) LIMIT 100
查询presto api如下