mysqli_free_result()函數(shù)釋放結(jié)果內(nèi)存。
一個PHP結(jié)果對象（mysqli_result類）表示由SELECT或DESCRIBE或EXPLAIN查詢返回的MySQL結(jié)果。
mysqli_free_result()函數(shù)接受一個結(jié)果對象作為參數(shù)，并釋放與它相關(guān)聯(lián)的內(nèi)存。
mysqli_free_result($result);
| 序號 | 參數(shù)及說明 |
|---|---|
| 1 | result(必需) 這是表示結(jié)果對象的標識符。 |
此函數(shù)不返回任何值。
此函數(shù)最初是在PHP版本5中引入的，并且可以在所有更高版本中使用。
以下示例演示了mysqli_free_result()函數(shù)的用法（面向過程風格），從結(jié)果集中獲取行，然后釋放結(jié)果集內(nèi)存：
<?php
$con = mysqli_connect("localhost", "root", "password", "mydb");
mysqli_query($con, "CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
print("創(chuàng)建表.....\n");
mysqli_query($con, "INSERT INTO myplayers values(1, 'Sikhar', 'Dhawan', 'Delhi', 'India')");
mysqli_query($con, "INSERT INTO myplayers values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
mysqli_query($con, "INSERT INTO myplayers values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
print("插入記錄.....\n");
//檢索表的內(nèi)容
$res = mysqli_query($con, "SELECT * FROM myplayers");
print("Contents of the resultset...\n");
//結(jié)果集的內(nèi)容
while ($row = mysqli_fetch_row($res)) {
print("ID: ".$row[0]."\n");
print("First_Name: ".$row[1]."\n");
print("Last_Name: ".$row[2]."\n");
print("Place_Of_Birth: ".$row[3]."\n");
print("Country: ".$row[4]."\n");
}
//結(jié)束語句，釋放內(nèi)存
mysqli_free_result($res);
//關(guān)閉連接
mysqli_close($con);
?>輸出結(jié)果
創(chuàng)建表..... 插入記錄..... Contents of the resultset... ID: 1 First_Name: Sikhar Last_Name: Dhawan Place_Of_Birth: Delhi Country: India ID: 2 First_Name: Jonathan Last_Name: Trott Place_Of_Birth: CapeTown Country: SouthAfrica ID: 3 First_Name: Kumara Last_Name: Sangakkara Place_Of_Birth: Matale Country: Srilanka
如果您嘗試在將結(jié)果釋放為后獲取結(jié)果的內(nèi)容-
$con = mysqli_connect("localhost", "root", "password", "mydb");
mysqli_query($con, "CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
print("創(chuàng)建表.....\n");
mysqli_query($con, "INSERT INTO myplayers values(1, 'Sikhar', 'Dhawan', 'Delhi', 'India')");
mysqli_query($con, "INSERT INTO myplayers values(2, 'Jonathan', 'Trott', 'CapeTown', 'SouthAfrica')");
mysqli_query($con, "INSERT INTO myplayers values(3, 'Kumara', 'Sangakkara', 'Matale', 'Srilanka')");
print("插入記錄.....\n");
//檢索表的內(nèi)容
$res = mysqli_query($con, "SELECT * FROM myplayers");
//結(jié)束語句
mysqli_free_result($res);
print("結(jié)果集的內(nèi)容...\n");
//結(jié)果集的內(nèi)容
while ($row = mysqli_fetch_row($res)) {
print("ID: ".$row[0]."\n");
print("First_Name: ".$row[1]."\n");
print("Last_Name: ".$row[2]."\n");
print("Place_Of_Birth: ".$row[3]."\n");
print("Country: ".$row[4]."\n");
}
//關(guān)閉連接
mysqli_close($con);您將收到如下所示的錯誤
創(chuàng)建表..... 插入記錄..... 結(jié)果集的內(nèi)容... PHP Warning: mysqli_fetch_row(): Couldn't fetch mysqli_result in E:\PHPExamples\procedure_oriented.php on line 19 Warning: mysqli_fetch_row(): Couldn't fetch mysqli_result in E:\PHPExamples\procedure_oriented.php on line 19
在面向?qū)ο箫L格中，此函數(shù)的語法為$ result-> close();。以下是面向?qū)ο箫L格中此函數(shù)的示例；
<?php
//建立連接
$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("創(chuàng)建表.....\n");
$stmt = $con -> prepare( "SELECT * FROM Test WHERE Name in(?, ?)");
$stmt -> bind_param("ss", $name1, $name2);
$name1 = 'Raju';
$name2 = 'Rahman';
//執(zhí)行語句
$stmt->execute();
//檢索結(jié)果
$result = $stmt->get_result();
//行數(shù)
$count = $result->num_rows;
print("結(jié)果中的行數(shù): ".$count);
//Closing the result
$result->close();
//結(jié)束語句
$stmt->close();
//關(guān)閉連接
$con->close();
?>輸出結(jié)果
創(chuàng)建表..... 結(jié)果中的行數(shù): 2