如何计算用户运行的命令数？

Question

我有一个 table 看起来像这样

user_id   ...
1         ...
1         ...
2         ...

我想要一个看起来像这样的table

user_id   num_commands   ...
1         2              ...
2         1              ...

我正在使用查询

select
user_id as id,
count(user_id) as num_commands,
...
from table_name
group by user_id

但它返回错误 FAILED: SemanticException [Error 10025]: Line 4:0 Expression not in GROUP BY key 'num_commands'。这对我来说似乎很荒谬；我意识到 num_commands 不在 GROUP BY 语句中，但它是聚合函数的结果，那么它为什么重要？

Answer 1

这是错误的

select
 user_id as id,
 count(user_id) as num_commands
 from table_name
 group by user_id

count(user_id) 并按 user_id 分组引发异常

select
 user_id as id,
 count(user_id) as num_commands,
 other_column1, 
 other_column2 
 from table_name
 group by user_id

这是错误的，因为分组依据

中的列不是

没错

select
 user_id as id,
 count(*) as num_commands,
 other_column1, 
 other_column2 
 from table_name
 group by user_id, other_column1,      other_column2 


select
 user_id as id,
 count(*) as num_commands,
 sum(other_column1), 
 avg(other_column2) 
 from table_name
 group by user_id

如何计算用户运行的命令数？

How do I count the number of commands a user ran?

sql

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如何计算用户 运行 的命令数？

How do I count the number of commands a user ran?

sql

hive

hiveql

如何计算用户运行的命令数？