Yes, I tried that. It produces the following SQL:
SELECT json_value(user.meta, :json_value_1) AS code
FROM user
HAVING json_value(user.meta, :json_value_1) IS NOT NULL
This make sense in general, because in MySQL you cannot refer to an alias
in the WHERE part.
But I want to refer directly to the alias, which is possible in HAVING
clauses (MySQL extension).
Le vendredi 22 juin 2018 03:40:23 UTC+3, Mike Bayer a écrit :
>
> Did you try using the code object itself? There's some dialect-specific
> rules for when it rewrites the expression vs. uses the label name in the
> expression but it may work (am traveling and can't check the code right now)
>
> On Thu, Jun 21, 2018, 10:10 AM <yoch....@gmail.com <javascript:>> wrote:
>
>> Hi,
>>
>> I want to translate this MariaDB query to sqlalchemy :
>>
>> SELECT JSON_VALUE(user.meta, '$.code') AS code
>> FROM user
>> HAVING code IS NOT NULL;
>>
>> (Note: the use of HAVING is because I want to filter on the alias `code`.)
>>
>> I don't find a simple way to use the alias in comparison, currently I
>> wrote this code :
>>
>> code = func.json_value(User.meta, '$.code').label('code')
>> db.query(code).having(literal_column(code.name)!=None).all()
>>
>> Is this correct ? Is there any better way to do that ?
>>
>> Thank you
>>
>> --
>> 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
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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
Example. See http://stackoverflow.com/help/mcve for a full description.
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