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Inconsistent behaviour in group by and order by

sebasv
New Contributor II

Consider this minimal example:

with t as (select explode(sequence(1,10,1)) as id)
select (id%2) as id from t
group by id
order by id

I would expect an ambiguous column name exception, since the grouping and sorting could apply to 2 different `id` columns. Instead the grouping is applied to t.id and the order is applied to (t.id%2).

Is there a setting we can apply to trigger an error when there is ambiguity? Can this be escalated?

2 REPLIES 2

gchandra
Databricks Employee
Databricks Employee

SathyaSDE
Contributor

Hi,

This is not an issue, pls understand order of execution of SQL queries. "Order by" clause will always refer to columns selected / displayed (as you are referring as id everywhere I guess there is a confusion).

SathyaSDE_0-1729949420766.pngSathyaSDE_1-1729949460154.png

Ambiguous column name exception occurs when you refer same column names from two tables without aliasing it differently.

I hope it helps!!

 

 

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