Rust - mysql 增刪改查

一、添加mysql依賴

mysql_async 是基於tokio2.0的異步mysql

[dependencies]
mysql_async = "0.22.2"
tokio = "0.2.13"

二、設置database_url，創建連接池

DSN：mysql://root:[email protected]:3306/testdb?pool_min=10&pool_max=100&conn_ttl=10

?後面的參數列表：

• pool_min：連接池最小值，默認10
• pool_max：連接池最大值，默認100
• inactive_connection_ttl：默認0秒，如果空閒連接時長大於ttl，連接數也大於pool_min，就關閉
• ttl_check_interval：默認30秒，ttl檢測週期，每隔30秒檢查一下空間連接的狀態
• conn_ttl：默認爲wait_timeout，如果最後一次IO執行的時長大於ttl，則關閉該連接
• tcp_keepalive：默認爲None，tcp保持連接狀態的時長，毫秒單位
• tcp_nodelay：默認爲true，是否啓用TCP_NODELAY選項
• stmt_cache_size：默認10條，緩存準備好的stmt語句
• prefer_socket：是否查詢@@socket變量
• socket：默認爲None，Unix套接字（或Windows上的命名管道）的路徑
• compression：默認None，壓縮快慢，（fast = 1、on = true、best = 9，0~9）

創建連接池

let pool = mysql_async::Pool::new(database_url);

從連接池獲取一個connect，當離開作用域，調用drop自動返還給pool

let conn = pool.get_conn().await?;

程序退出，需要手動關閉連接池

pool.disconnect().await?;

三、執行sql的幾種函數調用

1、ping，判斷mysql服務器是否可用

let conn = conn.ping().await?;

2、query，普通的查詢，需要自己判斷sql參數是否正確

let result = conn.query("SELECT * FROM t_user").await?;

3、prep_exec，使用stmt語句查詢

let result = conn.prep_exec("SELECT * FROM user where id = :id", params! {
    "id" => 1
}).await?;

4、只查詢一條結果集

let (conn, row): (_, Option<Row>) = conn.first_exec("SELECT * FROM user where id = :id", params! {
    "id" => 1
}).await?;

5、執行sql，不關心result結果集

    let conn = match conn.drop_exec(r"CREATE TABLE `t_user` (
      `id` INT(11) NOT NULL AUTO_INCREMENT,
      `username` VARCHAR(255) COLLATE utf8_unicode_ci NOT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=INNODB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci", ()).await {
        Ok(conn) => conn,
        Err(e) => panic!("has error")
    };

6、批量執行sql

// params是param!參數的集合
let conn = conn.batch_exec(r"INSERT INTO payment (customer_id, amount, account_name) 
VALUES (:customer_id, :amount, :account_name)", params).await?;

7、事務處理

let mut trOpts = TransactionOptions::new();
trOpts.set_isolation_level(IsolationLevel::RepeatableRead);

let tr = pool.start_transaction(trOpts).await?;

let (tr, row): (_, Option<Row>) = tr.first_exec("SELECT * FROM user where id = :id", params! {
    "id" => 1
}).await?;

tr.commit().await?;

println!("{:?}", row);

四、處理查詢結果集Rows

1、使用mysql_async::from_row()，獲取column的tuple結果

    let result = conn.prep_exec("SELECT username, email FROM user where id = :id", params! {
        "id" => 1
    }).await?;

    let (_, user_info) = result.map_and_drop(|row| {
        let (username, email): (Option<String>, Option<String>) = mysql_async::from_row(row);

        (username, email)
    }).await?;

    println!("{:?}", user_info);

2、使用row本身的函數get按照index索引，或者column的名字來獲取

    let result = conn.prep_exec("SELECT username, email FROM user where id = :id", params! {
        "id" => 1
    }).await?;

    let (_, user_info) = result.map_and_drop(|row| {
        let username: Option<String> = row.get("username");
        let email: Option<String> = row.get("email");

        (username, email)
    }).await?;

    println!("{:?}", user_info);