PHP: MySQL 拡張モジュールの概要を示す例

MySQL 拡張モジュールの概要を示す例

以下は、MySQL データベースに接続し、クエリを実行し、結果レコードを出力、接続を切断する例です。

例1 MySQL 拡張モジュールに関する例

<?php
// データベースに接続し、選択する
$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')
    or die('Could not connect: ' . mysql_error());
echo 'Connected successfully';
mysql_select_db('my_database') or die('Could not select database');

// SQL クエリを実行する
$query = 'SELECT * FROM my_table';
$result = mysql_query($query) or die('Query failed: ' . mysql_error());

// HTML に結果を出力する
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
    echo "\t<tr>\n";
    foreach ($line as $col_value) {
        echo "\t\t<td>$col_value</td>\n";
    }
    echo "\t</tr>\n";
}
echo "</table>\n";

// 結果セットを開放する
mysql_free_result($result);

// 接続を閉じる
mysql_close($link);
?>

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User Contributed Notes 1 note

down

-30

zjrwjzzz at 163 dot com ¶

9 years ago

Be aware that if you are trying to foreach the associative array returned by mysql_fetch_array() with MYSQL_ASSOC or mysql_fetch_assoc(), you have to ensure the return value that is used in foreach structure is exactly a array rather than a FALSE value. 

Or you might encounter the warning below: 
    Warning: Invalid argument supplied for foreach()

Here is an example (assume that $result have already stored the return value from mysql_query()):

If you have some block of code like:

<?php 

// Printing results in HTML
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
    echo "\t<tr>\n";
    foreach ($line as $col_value) {
        echo "\t\t<td>$col_value</td>\n";
    }
    echo "\t</tr>\n";
}
echo "</table>\n";

?>

If this is the case, you should use the code below instead:

<?php 

// Check ahead, before using it
if (mysql_num_rows($result) > 0) {
    // Printing results in HTML
    echo "<table>\n";
    while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
        echo "\t<tr>\n";
        foreach ($line as $col_value) {
            echo "\t\t<td>$col_value</td>\n";
        }
        echo "\t</tr>\n";
    }
    echo "</table>\n";
}

?>

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