The sql query itself returns several rows, as it should. But when trying 
to combine the max using sqlalchemy the rows return as the following.

Received incompatible instance "(server.db.models.Data object at , 
'2021-04-10 18', Decimal('7294.00000'))".", 

Here I am able to get the max for that row group, but am unable to pass it 
into the DataModel object


On Tuesday, April 11, 2023 at 4:59:15 PM UTC-7 S Mahabl wrote:

> Do you get many rows?
>
> SELECT  date_format(data.timestamp, "%Y-%m-%d %H"), max(data.value)  AS 
> data_value
> from data
> GROUP BY date_format(data.timestamp, "%Y-%m-%d %H")
> On Tue, Apr 11, 2023 at 4:24 PM Luis Del Rio IV <[email protected]> 
> wrote:
>
>> Hello,
>>
>> I am currently using the following sqlalchemy code,
>>
>>         _query = super().get_query(model, info, sort, **args)
>>         query = _query.group_by(
>>             func.date_format(DataModel.timestamp, "%Y-%m-%d %H")
>>         )
>>         return query
>>
>> I am trying to aggregate the the max value of a field from 
>> DataModel.value utilizing the group by clause.
>>
>> In simple sql, you would do the following.
>>
>> SELECT  max(data.value)  AS data_value
>> from data
>> GROUP BY date_format(data.timestamp, "%Y-%m-%d %H")
>>
>> What would the proper way to express this? The various methods I have 
>> tried somehow overwrite the original query and do not map to our attributes.
>>
>> -- 
>> SQLAlchemy - 
>> The Python SQL Toolkit and Object Relational Mapper
>>  
>> http://www.sqlalchemy.org/
>>  
>> To post example code, please provide an MCVE: Minimal, Complete, and 
>> Verifiable Example. See http://stackoverflow.com/help/mcve for a full 
>> description.
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>> .
>>
>

-- 
SQLAlchemy - 
The Python SQL Toolkit and Object Relational Mapper

http://www.sqlalchemy.org/

To post example code, please provide an MCVE: Minimal, Complete, and Verifiable 
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