Unable to group by date

[kakalos12]

Setup

Versions

• **Rust:1.76.0
• **Diesel:2
• **Database:mysql
• Operating System

Feature Flags

• **diesel:2

Problem Description

Thanks so much for a great project.
While working with a feature to sum all the user_transactions and create a statistics by date, I have a problem with the group_by function that I don't find any solution on the internet. Please help.

Thanks so much
This code does not compile :

   user_transactions::table
        .group_by(date(user_transactions::created_at))
        .select((
            sum(user_transactions::cash),
            date(user_transactions::created_at),
        ))
        .filter(user_transactions::user_id.eq(user_id))
        .filter(user_transactions::transaction_type.eq(UserTransactionType::Commission))
        .load::<(i64, NaiveDate)>(conn)
        .await
       .map_err(anyhow::Error::from)

What are you trying to accomplish?

What is the expected output?

What is the actual output?

.select((
| ^^^^^^ the trait IsContainedInGroupBy<user_transactions::columns::created_at> is not implemented for functions::date_and_time::date::date<user_transactions::columns::created_at>
--> app/src/repository/user_transaction.rs:48:10
|
48 | .select((
| ^^^^^^ the trait IsContainedInGroupBy<user_transactions::columns::created_at> is not implemented for functions::date_and_time::date::date<user_transactions::columns::created_at>
|
= help: the following other types implement trait IsContainedInGroupBy<T>:
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::updated_at>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::created_at>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::notes>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::status>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::amount>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::user_id>
<withdrawals::columns::updated_at as IsContainedInGroupBywithdrawals::columns::id>
<withdrawals::columns::created_at as IsContainedInGroupBywithdrawals::columns::updated_at>
and 1428 others
note: required for user_transactions::columns::created_at to implement ValidGrouping<functions::date_and_time::date::date<user_transactions::columns::created_at>>
--> app/src/schema.rs:316:9
|
316 | created_at -> Timestamp,
| ^^^^^^^^^^
= note: 1 redundant requirement hidden
= note: required for (sum<Integer, cash>, date<created_at>) to implement ValidGrouping<functions::date_and_time::date::date<user_transactions::columns::created_at>>
= note: the full type name has been written to '/app/target/debug/deps/app-8840f9eb5889a010.long-type-1122692697415527159.txt'
= note: required for SelectStatement<FromClause<table>, DefaultSelectClause<FromClause<table>>, ..., ..., ..., ..., ...> to implement SelectDsl<(functions::aggregate_folding::sum::sum<diesel::sql_types::Integer, user_transactions::columns::cash>, functions::date_and_time::date::date<user_transactions::columns::created_at>)>
= note: the full type name has been written to '/app/target/debug/deps/app-8840f9eb5889a010.long-type-17702273429917501699.txt'

Are you seeing any additional errors?

Steps to reproduce

Checklist

• I have already looked over the issue tracker and the discussion forum for similar possible closed issues.

• This issue can be reproduced on Rust's stable channel. (Your issue will be
  closed if this is not the case)
• This issue can be reproduced without requiring a third party crate

[weiznich]

Thanks for filling this Bug report.
I fear that this is currently just not supported by the built-in DSL. We certainly would accept a PR that extends what is possible to express in terms of valid GROUP BY clauses.