how to using rust diesel to do the group by query - rust

Question

I am using rust diesel diesel = { version = "1.4.8", features = ["postgres","64-column-tables","chrono","serde_json"] } to do the group by query follow the docs like this:
fpub fn get_bill_book_account_sum(){
use crate::diesel::GroupByDsl;
use diesel::dsl::max;
use crate::model::diesel::dict::dict_schema::test as bill_record_table;
let source_query = bill_record_table::table
.group_by(bill_record_table::id)
.select((max(bill_record_table::tags),bill_record_table::id))
.filter(bill_record_table::dsl::tags.eq(9));
}
then compile this code, shows error like this:
error[E0277]: the trait bound `aggregate_ordering::max::max<BigInt, columns::tags>: NonAggregate` is not satisfied
--> src/main.rs:19:17
|
19 | .select((max(bill_record_table::tags),bill_record_table::id))
| ------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NonAggregate` is not implemented for `aggregate_ordering::max::max<BigInt, columns::tags>`
| |
| required by a bound introduced by this call
|
= note: required because of the requirements on the impl of `diesel::Expression` for `(aggregate_ordering::max::max<BigInt, columns::tags>, columns::id)`
note: required by a bound in `diesel::QueryDsl::select`
--> /Users/xiaoqiangjiang/.cargo/registry/src/mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd/diesel-1.4.8/src/query_dsl/mod.rs:291:20
|
291 | Selection: Expression,
| ^^^^^^^^^^ required by this bound in `diesel::QueryDsl::select`
For more information about this error, try `rustc --explain E0277`.
error: could not compile `rust-learn` due to previous error
where am I doing wrong? what should I do to fixed this problem? this is the schema define(I have removed all the columns just using 2 columns to make a minimal reproduce example):
table! {
test (id) {
id -> Int8,
tags -> Int8,
}
}
and this is the model define:
// Generated by diesel_ext
#![allow(unused)]
#![allow(clippy::all)]
use std::io::Write;
use diesel::deserialize::FromSql;
use diesel::pg::Pg;
use diesel::serialize::{Output, ToSql};
use diesel::sql_types::Jsonb;
use rocket::serde::Serialize;
use serde::Deserialize;
use crate::model::diesel::dict::dict_schema::*;
#[derive(Queryable,Debug,Serialize,Deserialize,Default)]
pub struct Test {
pub id: i64,
pub tags: i64,
}
this is the minimal main.rs entrypoint:
#[macro_use]
extern crate diesel;
mod model;
use diesel::{ ExpressionMethods, QueryDsl};
fn main() {
get_bill_book_account_sum();
}
pub fn get_bill_book_account_sum(){
use crate::diesel::GroupByDsl;
use diesel::dsl::max;
use crate::model::diesel::dict::dict_schema::test as bill_record_table;
let source_query = bill_record_table::table
.group_by(bill_record_table::id)
.select((max(bill_record_table::tags),bill_record_table::id))
.filter(bill_record_table::dsl::tags.eq(9));
}

Answer 1

change the aggregate query like this fixed this problem:
pub fn get_bill_book_account_sum(request: &BillAccountRequest) -> Result<Vec<(i64, i32)>, diesel::result::Error>{
use crate::diesel::GroupByDsl;
use crate::model::diesel::fortune::fortune_schema::bill_record as bill_record_table;
let source_query = bill_record_table::table
.group_by(bill_record_table::account_id)
.select((diesel::dsl::sql::<diesel::sql_types::BigInt>("SUM(CAST(amount AS Integer))"),bill_record_table::account_id))
.filter(bill_record_table::dsl::bill_book_id.eq(request.bill_book_id));
let result = source_query.load::<(i64,i32)>(&get_connection());
return result;
}
the solution come from this issue. This is the answer come from the maintainer that shows diesel 1.x did not support group by official.