本文将介绍Rust语言使用Actix-web和SeaORM库，数据库使用PostgreSQL，开发增删改查项目，同时可以通过Swagger UI查看接口文档和查看标准Rust文档

开始项目

首先创建新项目，名称为rusty_crab_api

cargo new rusty_crab_api

Cargo.toml

[dependencies]
sea-orm = { version = "1.0.0-rc.5", features = [ "sqlx-postgres", "runtime-tokio-native-tls", "macros" ] }
tokio = { version = "1.35.1", features = ["full"] }
chrono = "0.4.33"
actix-web = "4.4.0"
serde = { version = "1.0", features = ["derive"] }
utoipa = { version = "4", features = ["actix_extras"] }
utoipa-swagger-ui = { version = "4", features = ["actix-web"] }
serde_json = "1.0"

使用SeaORM作为ORM工具，它提供了sea-orm-cli​工具，方便生成entity

PostgreSQL创建数据库

CREATE TABLE "user" (
  id SERIAL PRIMARY KEY,
  username VARCHAR(32) NOT NULL,
  birthday TIMESTAMP,
  sex VARCHAR(10),
  address VARCHAR(256)
);

COMMENT ON COLUMN "user".username IS '用户名称';
COMMENT ON COLUMN "user".birthday IS '生日';
COMMENT ON COLUMN "user".sex IS '性别';
COMMENT ON COLUMN "user".address IS '地址';

安装sea-orm-cli​

cargo install sea-orm-cli

生成entity

sea-orm-cli generate entity -u postgres://[用户名]:[密码]@[IP]:[PORT]/[数据库] -o src/entity

自动帮我们生成src./entity/user.rs文件

#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Eq, Serialize, Deserialize)]
#[sea_orm(table_name = "user")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub username: String,
    pub birthday: Option<DateTime>,
    pub sex: Option<String>,
    pub address: Option<String>,
}

#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
pub enum Relation {}

impl ActiveModelBehavior for ActiveModel {}

接下来编写接口函数，新建src/handlers/user.rs，编写用户表的增删改查代码，同时在代码文件中编写说明文档，提供给Rust标准文档和Swagger UI使用

/// 表示创建新用户的请求体结构
#[derive(Debug, Deserialize, ToSchema)]
#[schema(example = json!({
    "username": "johndoe",
    "birthday": "2023-09-09T15:53:00",
    "sex": "male",
    "address": "123 Main St, Anytown, USA"
}))]
pub struct CreateUser {
    /// 用户名  
    pub username: String,
    /// 生日（可选）
    #[schema(value_type = String)]
    pub birthday: Option<DateTime>,
    /// 性别（可选）
    pub sex: Option<String>,
    /// 地址（可选）
    pub address: Option<String>,
}
/// 创建新用户
///
/// # 请求体
///
/// 需要一个JSON对象，包含以下字段：
/// - `username`: 字符串，用户名（必填）
/// - `birthday`: ISO 8601格式的日期时间字符串，用户生日（可选）
/// - `sex`: 字符串，用户性别（可选）
/// - `address`: 字符串，用户地址（可选）
///
/// # 响应
///
/// - 成功：返回状态码200和新创建的用户JSON对象
/// - 失败：返回状态码500
///
/// # 示例
///
/// ‍‍```
/// POST /users
/// Content-Type: application/json
///
/// {
///     "username": "johndoe",
///     "birthday": "1990-01-01T00:00:00",
///     "sex": "M",
///     "address": "123 Main St, Anytown, USA"
/// }
/// ‍‍```
#[utoipa::path(
    post,
    path = "/api/users",
    request_body = CreateUser,
    responses(
        (status = 200, description = "User created successfully", body = Model),
        (status = 500, description = "Internal server error")
    )
)]
pub async fn create_user(
    db: web::Data<sea_orm::DatabaseConnection>,
    user_data: web::Json<CreateUser>,
) -> impl Responder {
    let user = UserActiveModel {
        username: Set(user_data.username.clone()),
        birthday: Set(user_data.birthday),
        sex: Set(user_data.sex.clone()),
        address: Set(user_data.address.clone()),
        ..Default::default()
    };

    let result = user.insert(db.get_ref()).await;

    match result {
        Ok(user) => HttpResponse::Ok().json(user),
        Err(_) => HttpResponse::InternalServerError().finish(),
    }
}
/// 获取指定ID的用户信息
///
/// # 路径参数
///
/// - `id`: 整数，用户ID
///
/// # 响应
///
/// - 成功：返回状态码200和用户JSON对象
/// - 未找到：返回状态码404
/// - 失败：返回状态码500
///
/// # 示例
///
/// ‍‍```
/// GET /users/1
/// ‍‍```
#[utoipa::path(
    get,
    path = "/api/users/{id}",
    responses(
        (status = 200, description = "User found", body = Model),
        (status = 404, description = "User not found"),
        (status = 500, description = "Internal server error")
    ),
    params(
        ("id" = i32, Path, description = "User ID")
    )
)]
pub async fn get_user(
    db: web::Data<sea_orm::DatabaseConnection>,
    id: web::Path<i32>,
) -> impl Responder {
    let user = user::Entity::find_by_id(*id).one(db.get_ref()).await;
    println!("{id}");
    match user {
        Ok(Some(user)) => HttpResponse::Ok().json(user),
        Ok(None) => HttpResponse::NotFound().finish(),
        Err(_) => HttpResponse::InternalServerError().finish(),
    }
}
/// 更新指定ID的用户信息
///
/// # 路径参数
///
/// - `id`: 整数，用户ID
///
/// # 请求体
///
/// 需要一个JSON对象，包含以下字段（所有字段都是可选的）：
/// - `username`: 字符串，新的用户名
/// - `birthday`: ISO 8601格式的日期时间字符串，新的用户生日
/// - `sex`: 字符串，新的用户性别
/// - `address`: 字符串，新的用户地址
///
/// # 响应
///
/// - 成功：返回状态码200和更新后的用户JSON对象
/// - 未找到：返回状态码404
/// - 失败：返回状态码500
///
/// # 示例
///
/// ‍‍```
/// PUT /users/1
/// Content-Type: application/json
///
/// {
///     "username": "johndoe_updated",
///     "address": "456 Elm St, Newtown, USA"
/// }
/// ‍‍```
#[utoipa::path(
    put,
    path = "/api/users/{id}",
    request_body = CreateUser,
    responses(
        (status = 200, description = "User updated successfully", body = Model),
        (status = 404, description = "User not found"),
        (status = 500, description = "Internal server error")
    ),
    params(
        ("id" = i32, Path, description = "User ID")
    )
)]
pub async fn update_user(
    db: web::Data<sea_orm::DatabaseConnection>,
    id: web::Path<i32>,
    user_data: web::Json<CreateUser>,
) -> impl Responder {
    let user = user::Entity::find_by_id(*id).one(db.get_ref()).await;

    match user {
        Ok(Some(user)) => {
            let mut user: UserActiveModel = user.into();
            user.username = Set(user_data.username.clone());
            user.birthday = Set(user_data.birthday);
            user.sex = Set(user_data.sex.clone());
            user.address = Set(user_data.address.clone());

            let result = user.update(db.get_ref()).await;

            match result {
                Ok(updated_user) => HttpResponse::Ok().json(updated_user),
                Err(_) => HttpResponse::InternalServerError().finish(),
            }
        }
        Ok(None) => HttpResponse::NotFound().finish(),
        Err(_) => HttpResponse::InternalServerError().finish(),
    }
}
/// 删除指定ID的用户
///
/// # 路径参数
///
/// - `id`: 整数，用户ID
///
/// # 响应
///
/// - 成功：返回状态码204（无内容）
/// - 失败：返回状态码500
///
/// # 示例
///
/// ‍‍```
/// DELETE /users/1
/// ‍‍```
#[utoipa::path(
    delete,
    path = "/api/users/{id}",
    responses(
        (status = 204, description = "User deleted successfully"),
        (status = 500, description = "Internal server error")
    ),
    params(
        ("id" = i32, Path, description = "User ID")
    )
)]
pub async fn delete_user(
    db: web::Data<sea_orm::DatabaseConnection>,
    id: web::Path<i32>,
) -> impl Responder {
    let result = user::Entity::delete_by_id(*id).exec(db.get_ref()).await;

    match result {
        Ok(_) => HttpResponse::NoContent().finish(),
        Err(_) => HttpResponse::InternalServerError().finish(),
    }
}

为了使用Swagger UI查看接口文档，还需要创建src/api_doc.rs文件

#[derive(OpenApi)]
#[openapi(
    paths(
        handlers::user::create_user,
        handlers::user::get_user,
        handlers::user::update_user,
        handlers::user::delete_user
    ),
    components(
        schemas(Model,CreateUser)
    ),
    tags(
        (name = "users", description = "User management API")
    )
)]
pub struct ApiDoc;

在src/main.rs文件定义路由和配置Swagger UI

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let db: DatabaseConnection = db::establish_connection().await;
    let db_data = web::Data::new(db);

    HttpServer::new(move || {
        App::new()
            .app_data(db_data.clone())
            .service(
                web::scope("/api")
                    .service(
                        web::scope("/users")
                            .route("", web::post().to(create_user))
                            .route("/{id}", web::get().to(get_user))
                            .route("/{id}", web::put().to(update_user))
                            .route("/{id}", web::delete().to(delete_user))
                            .route("/test", web::get().to(|| async { "Hello, World!" }))
                    )
            )
            .service(
                SwaggerUi::new("/swagger-ui/{_:.*}")
                    .url("/api-docs/openapi.json", ApiDoc::openapi())
            )
    })
    .bind("127.0.0.1:8080")?
    .run()
    .await
}

到这里，项目完成开发，启动项目

cargo run

查看Swagger UI接口文档

浏览器打开http://localhost:8080/swagger-ui/​

可以看到我们在Rust代码文件中的注释说明，这对于接口使用人员和代码维护人员都非常友好，当然对于接口的简单测试，在这个页面也是非常方便去进行

查看Rust标准文档

cargo doc --open

最后

项目的完整代码可以查看我的仓库​：https://github.com/VinciYan/rusty_crab_api.git

后续，我还会介绍如何使用Rust语言Web开发框架Salvo和SeaORM结合开发WebAPI