PHP mysqli_stmt_free_result() 函数

定义和用法

mysqli_stmt_free_result() 函数接受一个（预处理）语句对象作为参数，并释放存储给定语句结果的内存（当您使用 mysqli_stmt_store_result() 函数存储结果时）。

语法

mysqli_stmt_free_result($stmt);

参数

返回值

PHP mysqli_stmt_free_result() 函数不返回任何值。

PHP 版本

此函数首次引入于 PHP 5 版本，并在所有后续版本中均有效。

示例

以下示例演示了 mysqli_stmt_free_result() 函数（在过程式风格中）的用法：

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

   mysqli_query($con, "CREATE TABLE Test(Name VARCHAR(255), AGE INT)");
   mysqli_query($con, "insert into Test values('Raju', 25),('Rahman', 30),('Sarmista', 27)");
   print("Table Created.....\n");

   //Reading records
   $stmt = mysqli_prepare($con, "SELECT * FROM Test");

   //Executing the statement
   mysqli_stmt_execute($stmt);

   //Storing the result
   mysqli_stmt_store_result($stmt);

   //Number of rows
   $count = mysqli_stmt_num_rows($stmt);
   print("Number of rows in the table: ".$count."\n");

   //Freeing the resultset
   mysqli_stmt_free_result($stmt);

   $count = mysqli_stmt_num_rows($stmt);
   print("Number of rows after freeing the result: ".$count."\n");

   //Closing the statement
   mysqli_stmt_close($stmt);

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

这将产生以下结果：

Table Created.....
Number of rows in the table: 3
Number of rows after freeing the result: 0

示例

在面向对象风格中，此函数的语法为 $stmt->free_result(); 以下是此函数在面向对象风格中的示例：

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

   $con -> query("CREATE TABLE Test(Name VARCHAR(255), AGE INT)");
   $con -> query("insert into Test values('Raju', 25),('Rahman', 30),('Sarmista', 27)");
   print("Table Created.....\n");

   $stmt = $con -> prepare( "SELECT * FROM Test");

   //Executing the statement
   $stmt->execute();

   //Storing the result
   $stmt->store_result();
   print("Number of rows ".$stmt ->num_rows);

   //Freeing the resultset memory
   $stmt->free_result();

   //Closing the statement
   $stmt->close();

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

这将产生以下结果：

Table Created.....
Number of rows: 3