# Rust Web Rokcet 系列 2 连接数据库 和 CURD 增删改查


使用的是 SQLite 数据库，实际上各种数据库都大同小异。已经有很多包帮助我们处理各种细节。目前 diesel 支持mysql，postgres和sqlite。*函数使用方法一般都在鼠标移动到函数上，显示出的文档中。换句话说，在 Ctrl+左键 点击进去显示的源文件的字里行间之中。*

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相关文档:

https://rocket.rs/v0.5-rc/guide/state/#databases

参考写法:

https://github.com/SergioBenitez/Rocket/tree/v0.5-rc/examples/databases

## 安装相关工具 SQLite 和 diesel_cli

介绍一下 Windows  SQLite 下安装方法 ，打开 SQLite 官网 的下载页。

https://www.sqlite.org/download.html

选择**Precompiled Binaries for Windows** 

64位机下载[sqlite-dll-win64-x64-3370200.zip](https://www.sqlite.org/2022/sqlite-dll-win64-x64-3370200.zip)  和[sqlite-tools-win32-x86-3370200.zip](https://www.sqlite.org/2022/sqlite-tools-win32-x86-3370200.zip)
32位机下载[sqlite-dll-win32-x86-3370200.zip](https://www.sqlite.org/2022/sqlite-dll-win32-x86-3370200.zip)和[sqlite-tools-win32-x86-3370200.zip](https://www.sqlite.org/2022/sqlite-tools-win32-x86-3370200.zip)

解压这两个压缩包所有文件到一个目录，并使用 微软的 生成工具 ，在目录下执行
```powershell
lib /def:sqlite3.def /machine:X64 /out:sqlite3.lib
```
然后将目录加入环境变量，然后打开终端执行：
```powershell
cargo install diesel_cli --no-default-features --features sqlite
```
## 编写 SQL 
打开 项目目录，执行
```powershell
diesel setup
diesel migration generate article
```
生成了migrations\2022-02-14-114903_article\up.sql和migrations\2022-02-14-114903_article\down.sql
然后写 up.sql 和 down.sql

migrations\2022-02-11-063903_product\up.sql
```sql
-- Your SQL goes here
CREATE TABLE article (
 id INTEGER NOT NULL PRIMARY KEY,
 title Text NOT NULL,
 author Text NOT NULL,
 content Text NOT NULL,
 created_at Text NOT NULL
)
```
migrations\2022-02-14-114903_article\down.sql
```sql
-- This file should undo anything in `up.sql`

DROP TABLE article;
```

创建项目根目录，和Cargo.toml同级。创建 .env 文件。写入
.env
```
DATABASE_URL=article.db
```
然后执行
```powershell
diesel migration run
```
diesel会自动创建一个article.db，这就是我们之后会使用到的数据库了。除此之外，还有src\schema.rs和 diesel.toml文件。
使用数据库工具，可以看到已经成功创建了一个表

{{< image src="https://cdn.ftls.xyz/images/2022/02/20220214200151.png" caption="创建数据表" >}}

## 添加依赖

在Cargo.toml中添加依赖
Cargo.toml
```toml
[package]
name = "teach_used"
version = "0.1.0"
edition = "2021"
authors = ["Kkbt <0@ftls.xyz>"]

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rocket = { version = "0.5.0-rc.1",features = ["json"]}
diesel = "1.4.8"

[dependencies.rocket_sync_db_pools]
version = "0.1.0-rc.1"
default-features = false
features = ["diesel_sqlite_pool"]
```

创建Rocket.toml 
Rocket.toml
```toml
[global.databases]
sqlite_main = { url = "article.db" }
```
然后在 main.rs 加入数据库连接，默认开启连接池。

```rust
#[macro_use]
extern crate diesel;

use rocket_sync_db_pools::database;

#[database("sqlite_main")]
pub struct MainDbConn(diesel::SqliteConnection);
```

其实 rocket_sync_db_pools::diesel 也是可用的。类似于 
```rust
use rocket_sync_db_pools::{database,diesel};

#[database("sqlite_main")]
pub struct MainDbConn(diesel::SqliteConnection);
```
但是我还没弄明白如何导入 `#[macro_use]` ,这个宏在 src\schema.rs 中 table 用到了。有人知道的话知会我一声。这样的应该不用引入 diesel = "1.4.8" 依赖了。

## CURD

然后修改 src\main.rs，src\module.rs，src\routes.rs 。

 src\main.rs :

```rust
#[macro_use]
extern crate rocket;

#[macro_use]
extern crate diesel;

mod module;
mod routes;
mod schema;

use rocket_sync_db_pools::database;
use routes::*;

#[database("sqlite_main")]
pub struct MainDbConn(diesel::SqliteConnection);

#[launch]
fn rocket() -> _ {
    rocket::build()
        // database
        .attach(MainDbConn::fairing())
        .mount("/", routes![index])
        // add api
        .mount("/", routes![get_all_articles, get_article_by_id])
        .mount("/", routes![post_article, put_article])
        .mount("/", routes![delete_all_articles, delete_article])
}
 
```
src\module.rs
```rust
use crate::schema::article;
use diesel::Insertable;
use rocket::serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, Clone, Debug, Queryable, Insertable)]
#[serde(crate = "rocket::serde")]
#[table_name = "article"]
pub struct Article {
    pub id: i32,
    pub title: String,
    pub author: String,
    pub content: String,
    pub created_at: String,
}
#[derive(Debug, Serialize, Deserialize, Queryable, Clone, Insertable, AsChangeset)]
#[serde(crate = "rocket::serde")]
#[table_name = "article"]
pub struct PostArticle {
    pub title: String,
    pub author: String,
    pub content: String,
    pub created_at: String,
}
```
src\routes.rs 简单写了 CURD ，具体可以看文档。函数使用方法一般都在鼠标移动到函数上，显示出的文档中。换句话说，在 Ctrl+左键 点击进去显示的源文件的字里行间之中。
```rust
use diesel::{prelude::*, QueryDsl, RunQueryDsl};
use rocket::serde::json::{serde_json::json, Json, Value};
use rocket::{delete, get, post, put, response::status::Created, response::Debug};

use crate::module::{Article, PostArticle};
use crate::schema::article;
use crate::MainDbConn;

type Result<T, E = Debug<diesel::result::Error>> = std::result::Result<T, E>;

#[get("/")]
pub fn index() -> Value {
    json!({"kkbt":"Hello, world!"})
}

// 查 all
#[get("/article")]
pub async fn get_all_articles(db: MainDbConn) -> Result<Json<Vec<Article>>> {
    let all = db
        .run(move |conn| article::table.load::<Article>(conn))
        .await?;

    Ok(Json(all))
}
// 查 by id
#[get("/article/<in_id>")]
pub async fn get_article_by_id(db: MainDbConn, in_id: i32) -> Option<Json<Article>> {
    db.run(move |conn| article::table.filter(article::id.eq(in_id)).first(conn))
        .await
        .map(Json)
        .ok()
}
// 增
#[post("/article", format = "json", data = "<in_article>")]
pub async fn post_article(
    db: MainDbConn,
    in_article: Json<PostArticle>,
) -> Result<Created<Json<PostArticle>>> {
    let article_in = in_article.clone();
    db.run(move |conn| {
        diesel::insert_into(article::table)
            .values(&article_in)
            .execute(conn)
    })
    .await?;
    Ok(Created::new("/").body(in_article))
}

// 改 by id
#[put("/article/<in_id>", format = "json", data = "<in_article>")]
pub async fn put_article(
    db: MainDbConn,
    in_id: i32,
    in_article: Json<PostArticle>,
) -> Result<Option<()>> {
    let affected = db
        .run(move |conn| {
            diesel::update(article::table.filter(article::id.eq(in_id)))
                .set(in_article.into_inner())
                .execute(conn)
        })
        .await?;
    Ok((affected == 1).then(|| ()))
}

// 删 by id
#[delete("/article/<in_id>")]
pub async fn delete_article(db: MainDbConn, in_id: i32) -> Result<Option<()>> {
    let affected = db
        .run(move |conn| {
            diesel::delete(article::table)
                .filter(article::id.eq(&in_id))
                .execute(conn)
        })
        .await?;
    Ok((affected == 1).then(|| ()))
}

// 删 all
#[delete("/article/all")]
pub async fn delete_all_articles(db: MainDbConn) -> Result<()> {
    db.run(move |conn| diesel::delete(article::table).execute(conn))
        .await?;

    Ok(())
}

```

本系列 Postman 分享链接:

https://www.getpostman.com/collections/c89ec512876818f18757

如果链接失效了，请只会一声。或 teach.postman_collection.json 如下

```json
{
	"info": {
		"_postman_id": "709bf03a-bdd4-4b98-afac-b01ae46d2b65",
		"name": "teach",
		"schema": "https://schema.getpostman.com/json/collection/v2.0.0/collection.json",
		"_exporter_id": "16599952"
	},
	"item": [
		{
			"name": "http://127.0.0.1:8000/",
			"request": {
				"method": "GET",
				"header": [],
				"url": "http://127.0.0.1:8000/"
			},
			"response": []
		},
		{
			"name": "获取所有文章",
			"request": {
				"method": "GET",
				"header": [],
				"url": "http://127.0.0.1:8000/article"
			},
			"response": []
		},
		{
			"name": "增加文章",
			"request": {
				"method": "POST",
				"header": [],
				"body": {
					"mode": "raw",
					"raw": "{\r\n    \"title\": \"a title\",\r\n    \"author\": \"恐咖兵糖\",\r\n    \"content\": \"dasdaadas\",\r\n    \"created_at\": \"2022-02-14 \"\r\n}",
					"options": {
						"raw": {
							"language": "json"
						}
					}
				},
				"url": "http://127.0.0.1:8000/article"
			},
			"response": []
		},
		{
			"name": "获取文章 by id",
			"request": {
				"method": "GET",
				"header": [],
				"url": "http://127.0.0.1:8000/article/2"
			},
			"response": []
		},
		{
			"name": "删除文章 by id",
			"request": {
				"method": "DELETE",
				"header": [],
				"url": "http://127.0.0.1:8000/article/3"
			},
			"response": []
		},
		{
			"name": "更新文章",
			"request": {
				"method": "PUT",
				"header": [],
				"body": {
					"mode": "raw",
					"raw": "{\r\n    \"title\": \"a title\",\r\n    \"author\": \"恐咖兵糖\",\r\n    \"content\": \"222ssss2\",\r\n    \"created_at\": \"2022-02-14 \"\r\n}",
					"options": {
						"raw": {
							"language": "json"
						}
					}
				},
				"url": "http://127.0.0.1:8000/article/4"
			},
			"response": []
		},
		{
			"name": "删除所有文章",
			"request": {
				"method": "DELETE",
				"header": [],
				"url": "http://127.0.0.1:8000/article/all"
			},
			"response": []
		},
		{
			"name": "获取token",
			"request": {
				"method": "POST",
				"header": [],
				"body": {
					"mode": "raw",
					"raw": "{\r\n    \"id\": 0,\r\n    \"key\": \"oR66T*W8y4VaXkh#rTjeZ$$Rby$NCy!nJX\"\r\n}",
					"options": {
						"raw": {
							"language": "json"
						}
					}
				},
				"url": "http://127.0.0.1:8000/token"
			},
			"response": []
		},
		{
			"name": "token 测试",
			"event": [
				{
					"listen": "prerequest",
					"script": {
						"exec": [
							"const gettoken = {\r",
							"    url: ' http://127.0.0.1:8000/token',\r",
							"    method: \"POST\",\r",
							"    header: 'Content-Type: application/json',\r",
							"    body: {\r",
							"        mode: 'raw', \r",
							"    raw: JSON.stringify({\"id\": 0, \"key\": \"oR66T*W8y4VaXkh#rTjeZ$$Rby$NCy!nJX\"}) //要将JSON对象转为文本发送\r",
							"\r",
							"    }\r",
							"}\r",
							"pm.sendRequest(gettoken, function (err, response) {\r",
							"    console.log(response.json().token);\r",
							"    pm.collectionVariables.set(\"token\",response.json().token);\r",
							"});"
						],
						"type": "text/javascript"
					}
				}
			],
			"request": {
				"method": "GET",
				"header": [
					{
						"key": "Authorization",
						"value": "Bearer {{token}}",
						"type": "default"
					}
				],
				"url": "http://127.0.0.1:8000/token/test"
			},
			"response": []
		}
	],
	"variable": [
		{
			"key": "token",
			"value": ""
		}
	]
}
```