0

我正在为我的 rust 应用程序编写一个数据库模块，使用柴油。

这是编译错误：

error[E0271]: type mismatch resolving `<MysqlConnection as Connection>::Backend == Sqlite`
   --> src/quant/common/persistence/database.rs:155:18
    |
155 |                 .load::<NetWorthModel>(&self.connection())
    |                  ^^^^ expected struct `Mysql`, found struct `Sqlite`
    |
    = note: required because of the requirements on the impl of `LoadQuery<MysqlConnection, NetWorthModel>` for `diesel::query_builder::SelectStatement<table, diesel::query_builder::select_clause::DefaultSelectClause, diesel::query_builder::distinct_clause::NoDistinctClause, diesel::query_builder::where_clause::WhereClause<And<And<diesel::expression::operators::Eq<columns::fund_code, diesel::expression::bound::Bound<diesel::sql_types::Text, &str>>, GtEq<columns::date, diesel::expression::bound::Bound<diesel::sql_types::Date, std::string::String>>>, Lt<columns::date, diesel::expression::bound::Bound<diesel::sql_types::Date, std::string::String>>>>, diesel::query_builder::order_clause::OrderClause<Asc<columns::date>>, diesel::query_builder::limit_clause::LimitClause<diesel::expression::bound::Bound<diesel::sql_types::BigInt, i64>>, diesel::query_builder::offset_clause::OffsetClause<diesel::expression::bound::Bound<diesel::sql_types::BigInt, i64>>>`

这是model.rs：

use super::schema::tb_net_worth;
use diesel::{Identifiable, Insertable, Queryable};

#[derive(Queryable, Insertable, Identifiable)]
#[table_name = "tb_net_worth"]
#[primary_key(fund_code)]
pub struct NetWorthModel {
    pub fund_code: String,
    pub date: String,
    pub create_time: i64,
    pub update_time: i64,
    pub payload: String,
}

这是我的源代码database.rs：

use crate::quant::common::persistence::model::NetWorthModel;
use crate::quant::common::yadatetime::Date;
use diesel::mysql::MysqlConnection;
use diesel::prelude::*;
use diesel::r2d2::{ConnectionManager, Pool};
use std::collections::HashMap;
use std::sync::Mutex;

pub struct MysqlDatabase {
  pool: Pool<ConnectionManager<MysqlConnection>>,
}

impl MysqlDatabase {
  fn new(user: &str, passwd: &str, host: &str, port: i32, db: &str) -> MysqlDatabase {
    let url = format!("mysql://{}:{}@{}:{}/{}", user, passwd, host, port, db);
    let pool_manager = ConnectionManager::<MysqlConnection>::new(url.as_str());
    let pool = Pool::builder()
                   .max_size(16)
                   .build(pool_manager)
                   .unwrap();
    MysqlDatabase {pool: pool.clone()}
  }

  fn connection(&self) -> MysqlConnection { 
    *self.pool.get().unwrap() 
  }

  fn paged_query(&self, 
                 fund_code: &str, 
                 order_by: &str, 
                 start_date: Date, 
                 end_date: Date, 
                 page_index: i32, 
                 page_size: i32) -> Vec[NetWorthModel] {
    use super::schema::tb_net_worth::dsl;
        
    let query = dsl::tb_net_worth
                     .filter(dsl::fund_code.eq(fund_code))
                     .filter(dsl::date.ge(start_date.to_string()))
                     .filter(dsl::date.lt(end_date.to_string()));
    if order_by == "ASC" {
      query.order(dsl::date.asc())
            .limit(page_size as i64)
            .offset((page_index * page_size) as i64)
            .load<NetWorthModel>(&self.connection())
            .unwrap()
    } else {
      query.order(dsl::date.desc()) 
            .limit(page_size as i64)
            .offset((page_index * page_size) as i64)
            .load<NetWorthModel>(&self.connection())
            .unwrap()
    }
  }

你能帮忙吗？

4

0 回答 0