PHP mysqli_refresh()用法及代碼示例

定義和用法

這個mysqli_refresh()函數刷新表，刷新日誌，刷新緩存。

用法

mysqli_refresh($con, options);

參數

Sr.No	參數及說明
1	con(Mandatory) 這是一個表示與 MySQL 服務器的連接的對象。
2	options(Mandatory) 這代表了MYSQL刷新命令的選項，可以通過逗號分隔來指定多個選項。 MYSQLI_REFRESH_GRANT MYSQLI_REFRESH_LOG MYSQLI_REFRESH_TABLES MYSQLI_REFRESH_HOSTS MYSQLI_REFRESH_STATUS MYSQLI_REFRESH_THREADS MYSQLI_REFRESH_SLAVE MYSQLI_REFRESH_MASTER

返回值

PHP mysqli_refresh() 函數返回一個布爾值，如果刷新操作成功，則為 true，否則為 false。

PHP版本

這個函數最初是在 PHP 版本 5 中引入的，適用於所有後續版本。

示例

以下示例演示了 mysqli_refresh() 函數的用法(程序風格) -

假設我們在數據庫 mydb 中創建了一個名為 my_team 的表，如下所示 -

CREATE TABLE my_team(
   ID INT PRIMARY KEY AUTO_INCREMENT,
   First_Name VARCHAR(255), 
   Last_Name VARCHAR(255), 
   Place_Of_Birth VARCHAR(255), 
   Country VARCHAR(255)
);

以下示例關閉自動提交選項並嘗試將記錄插入此表 -

<?php
   //Creating a connection
   $con = mysqli_connect("localhost", "root", "password", "mydb");

   //Setting auto commit to true
   mysqli_autocommit($con, False);

   //Inserting a records into the my_team table
   mysqli_query($con, "insert into my_team values(1, 'Shikhar', 'Dhawan', 'Delhi', 'India')");
   mysqli_query($con, "insert into my_team values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
   mysqli_query($con, "insert into my_team values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
   mysqli_query($con, "insert into my_team values(4, 'Virat', 'Kohli', 'Delhi', 'India')");

   //Closing the connection
   mysqli_close($con);
?>

由於我們關閉了 auto-commit 選項，添加的記錄將不會保存在數據庫中，如果您在 MySQL 中驗證表的內容，它將為空，如下所示 $minus;

mysql> select * from my_team;
Empty set (0.00 sec)

您可以使用 mysqli_query 函數將記錄刷新到表中，如下所示 $minus;

<?php
   //Creating a connection
   $con = mysqli_connect("localhost", "root", "password", "mydb");
   //Setting auto commit to true
   mysqli_autocommit($con, False);
   //Inserting a records into the my_team table
   mysqli_query($con, "insert into my_team values(1, 'Shikhar', 'Dhawan', 'Delhi', 'India')");
   mysqli_query($con, "insert into my_team values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
   mysqli_query($con, "insert into my_team values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
   mysqli_query($con, "insert into my_team values(4, 'Virat', 'Kohli', 'Delhi', 'India')");

   mysqli_refresh($con, MYSQLI_REFRESH_TABLES);

   //Closing the connection
   mysqli_close($con);

現在，如果您驗證表 my_team 的內容，您可以看到插入的記錄，如下所示 -

mysql> select * from my_team;
+----+------------+------------+----------------+-------------+
| ID | First_Name | Last_Name  | Place_Of_Birth | Country     |
+----+------------+------------+----------------+-------------+
|  1 | Shikhar    | Dhawan     | Delhi          | India       |
|  2 | Jonathan   | Trott      | CapeTown       | SouthAfrica |
|  3 | Kumara     | Sangakkara | Matale         | Srilanka    |
|  4 | Virat      | Kohli      | Delhi          | India       |
+----+------------+------------+----------------+-------------+
4 rows in set (0.00 sec)

示例

在麵向對象的風格中，這個函數的語法是 $con->refresh();以下是麵向對象樣式 $minus 中此函數的示例；

<?php
   $con = new mysqli("localhost", "root", "password", "mydb");

   //Inserting a records into the players table
   $con->query("CREATE TABLE IF NOT EXISTS players(First_Name VARCHAR(255), Last_Name VARCHAR(255), Country VARCHAR(255))");

   //Turning the auto-commit false
   $con->autocommit(FALSE);

   $con->query("insert into players values('Shikhar', 'Dhawan', 'India')");
   $con->query("insert into players values('Jonathan', 'Trott', 'SouthAfrica')");

   //refreshing the table
   $con->refresh(MYSQLI_REFRESH_TABLES);

   //Closing the connection
   $res = $con -> close();
?>

這將產生以下結果 -

Data Created......

如果您觀察數據庫中表的內容，您可以看到插入的記錄，如下所示 -

mysql> select * from players;
+------------+-----------+-------------+
| First_Name | Last_Name | Country     |
+------------+-----------+-------------+
| Shikhar    | Dhawan    | India       |
| Jonathan   | Trott     | SouthAfrica |
+------------+-----------+-------------+
2 rows in set (0.00 sec)

示例

<?php
  $connection_mysql = mysqli_connect("localhost","username","password","db");
   
   if (mysqli_connect_errno($connection_mysql)){
      echo "Failed to connect to MySQL:" . mysqli_connect_error();
   }   
   mysqli_refresh($connection_mysql,MYSQLI_REFRESH_LOG);
   mysqli_close($connection_mysql);
?>