我正在尝试在导航栏中动态添加categories，但它会继续发出此错误：
警告：mysqli_fetch_array（）要求参数1为mysqli_result，第11行的C：\ xampp \ htdocs \ includes \ navigation.php中给出布尔值
我的PHP代码：
<?php
$sql = "SELECT * FROM categories WHERE parent = 0";
$result=mysqli_query($db,$sql);
?>
<nav class="navbar navbar-default navbar-fixed-top">
<div class="container">
<a href="home.php" class="navbar-brand">Bizibay</a>
<ul class="nav navbar-nav">
<?php while($row=mysqli_fetch_array($result, MYSQLI_ASSOC)) : ?>
<!-- top menu items -->
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Men<span class="caret"></span></a>
<ul class="dropdown-menu" role="menu">
<li><a href="#">Shirts</a></li>
<li><a href="#">Pants</a></li>
<li><a href="#">Shoes</a></li>
<li><a href="#">Accessories</a></li>
</ul>
</li>
</ul>
<?php endwhile; ?>
</div>
</nav>
答案 0 :(得分：0)
试试这个版本。它包含：预准备语句，异常处理和错误报告/显示。我希望它能帮助您找到解决方案。乍一看，您的提取似乎返回NULL。所以问题出在mysqli_query()。
实际上我写了两个版本。您可以通过包含＆＃34; oopFunctions.php＆＃34;来使用OOP样式（我的推荐）。在＆＃34; index.php＆＃34;中，或者您可以通过包含＆＃34; proceduralFunctions.php＆＃34;来使用过程样式。 in＆＃34; index.php＆＃34;。
祝你好运！<?php
require_once 'configs.php';
require_once 'oopFunctions.php';
// require_once 'proceduralFunctions.php';
/*
* Activate PHP error reporting/display.
* Display ONLY on development code, NEVER on production code!
* ALWAYS resolve WARNINGS and ERRORS.
* I recommend to always resolve NOTICES too.
*/
activateErrorReporting(E_ALL, TRUE);
//activateErrorReporting(E_ALL, FALSE);
/**
* Enable internal report functions. This enables the exception handling,
* e.g. mysqli will not throw PHP warnings anymore, but mysqli exceptions
* (mysqli_sql_exception). They are catched in the try-catch block.
*
* MYSQLI_REPORT_ERROR: Report errors from mysqli function calls.
* MYSQLI_REPORT_STRICT: Throw a mysqli_sql_exception for errors instead of warnings.
*
* See:
* http://php.net/manual/en/class.mysqli-driver.php
* http://php.net/manual/en/mysqli-driver.report-mode.php
* http://php.net/manual/en/mysqli.constants.php
*/
$mysqliDriver = new mysqli_driver();
$mysqliDriver->report_mode = (MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
try {
$parent = 0;
// Create db connection.
$connection = createConnection(
MYSQL_HOST
, MYSQL_DATABASE
, MYSQL_USERNAME
, MYSQL_PASSWORD
, MYSQL_PORT
);
// Fetch categories by parent.
$categories = fetchCategoriesByParent($connection, $parent);
// Close db connection.
closeConnection($connection);
} catch (mysqli_sql_exception $e) {
echo 'Error: ' . $e->getCode() . ' - ' . $e->getMessage();
exit();
} catch (Exception $e) {
echo $e->getMessage();
exit();
}
/*
* Disable internal report functions.
*
* MYSQLI_REPORT_OFF: Turns reporting off.
*
* See:
* http://php.net/manual/en/class.mysqli-driver.php
* http://php.net/manual/en/mysqli-driver.report-mode.php
* http://php.net/manual/en/mysqli.constants.php
*/
$mysqliDriver->report_mode = MYSQLI_REPORT_OFF;
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Test categories</title>
<!-- Bootstrap -->
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" type="text/css" rel="stylesheet" />
<!-- jQuery -->
<script src="https://code.jquery.com/jquery-3.2.1.min.js" type="text/javascript" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
<!-- Bootstrap -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" type="text/javascript"></script>
</head>
<body>
<nav class="navbar navbar-default navbar-fixed-top">
<div class="container">
<a href="home.php" class="navbar-brand">
Bizibay
</a>
<ul class="nav navbar-nav">
<?php
foreach ($categories as $key => $category) {
?>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">
Men<span class="caret"></span>
</a>
<ul class="dropdown-menu" role="menu">
<li><a href="#">Shirts</a></li>
<li><a href="#">Pants</a></li>
<li><a href="#">Shoes</a></li>
<li><a href="#">Accessories</a></li>
</ul>
</li>
<?php
}
?>
</ul>
</div>
</nav>
</body>
</html>
<?php
/*
* ----------------
* Database configs
* ----------------
*/
define('MYSQL_HOST', '...');
define('MYSQL_PORT', '3306');
define('MYSQL_DATABASE', '...');
define('MYSQL_USERNAME', '...');
define('MYSQL_PASSWORD', '...');
<?php
/**
* Toggle error reporting.
*
* @param integer $level Error level.
* @param bool $displayErrors Display errors if TRUE, hide them otherwise.
* @return void
*/
function activateErrorReporting($level = E_ALL, $displayErrors = TRUE) {
error_reporting($level);
ini_set('display_errors', ($displayErrors ? 1 : 0));
}
/**
* Create a new db connection.
*
* @see http://php.net/manual/en/mysqli.construct.php
* @param string $host Host.
* @param string $dbname Database name.
* @param string $username Username.
* @param string $password Password.
* @param string $port [optional] Port.
* @return mysqli Db connection.
* @throws mysqli_sql_exception
*/
function createConnection($host, $dbname, $username, $password, $port = '3306') {
$connection = mysqli_connect($host, $username, $password, $dbname, $port);
if (!$connection) {
throw new Exception('Connect error: ' . mysqli_connect_errno() . ' - ' . mysqli_connect_error());
}
return $connection;
}
/**
* Close db connection.
*
* @param mysqli $connection Connection instance.
* @return void
* @throws Exception
*/
function closeConnection($connection) {
$connectionClosed = mysqli_close($connection);
if (!$connectionClosed) {
throw new Exception('The database connection can not be closed!');
}
}
/**
* Fetch categories by parent.
*
* @param mysqli $connection Connection instance.
* @param integer $parent Parent.
* @return array Categories list.
* @throws Exception
*/
function fetchCategoriesByParent($connection, $parent) {
$fetchedData = array();
/*
* The SQL statement to be prepared. Notice the so-called markers,
* e.g. the "?" signs. They will be replaced later with the
* corresponding values when using mysqli_stmt::bind_param.
*
* See: http://php.net/manual/en/mysqli.prepare.php
*/
$sql = 'SELECT * FROM categories WHERE parent = ?';
/*
* Prepare the SQL statement for execution.
*
* Throws mysqli_sql_exception.
* See: http://php.net/manual/en/mysqli.prepare.php
*/
$statement = mysqli_prepare($connection, $sql);
if (!$statement) {
throw new Exception('Prepare error: The sql statement can not be prepared!');
}
/*
* Bind variables for the parameter markers (?) in the
* SQL statement that was passed to mysqli::prepare. The first
* argument of mysqli_stmt::bind_param is a string that contains one
* or more characters which specify the types for the corresponding bind variables.
*
* See: http://php.net/manual/en/mysqli-stmt.bind-param.php
*/
$bound = mysqli_stmt_bind_param($statement, 'i', $parent);
if (!$bound) {
throw new Exception('Bind error: The variables could not be bound to the prepared statement!');
}
/*
* Execute the prepared SQL statement.
* When executed any parameter markers which exist will
* automatically be replaced with the appropriate data.
*
* See: http://php.net/manual/en/mysqli-stmt.execute.php
*/
$executed = mysqli_stmt_execute($statement);
if (!$executed) {
throw new Exception('Execute error: The prepared statement could not be executed!');
}
/*
* Get the result set from the prepared statement. In case of
* failure use errno, error and/or error_list to see the error.
*
* NOTA BENE:
* Available only with mysqlnd ("MySQL Native Driver")! If this
* is not installed, then uncomment "extension=php_mysqli_mysqlnd.dll" in
* PHP config file (php.ini) and restart web server (I assume Apache) and
* mysql service. Or use the following functions instead:
* mysqli_stmt::store_result + mysqli_stmt::bind_result + mysqli_stmt::fetch.
*
* See:
* http://php.net/manual/en/mysqli-stmt.get-result.php
* https://stackoverflow.com/questions/8321096/call-to-undefined-method-mysqli-stmtget-result
*/
$result = mysqli_stmt_get_result($statement);
if (!isset($result) || !$result) {
throw new Exception('Get result error: ' . mysqli_error($connection));
}
/*
* Get the number of rows in the result.
*
* See: http://php.net/manual/en/mysqli-result.num-rows.php
*/
$numberOfRows = mysqli_num_rows($result);
/*
* Fetch data and save it into $fetchedData array.
*
* See: http://php.net/manual/en/mysqli-result.fetch-array.php
*/
if ($numberOfRows > 0) {
// Fetch all rows at once.
$fetchedData = mysqli_fetch_all($result, MYSQLI_ASSOC);
// ...or fetch one row at a time.
// while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
// $fetchedData[] = $row;
// }
}
/*
* Free the memory associated with the result. You should
* always free your result when it is not needed anymore.
*
* See: http://php.net/manual/en/mysqli-result.free.php
*/
mysqli_free_result($result);
/*
* Close the prepared statement. It also deallocates the statement handle.
* If the statement has pending or unread results, it cancels them
* so that the next query can be executed.
*
* See: http://php.net/manual/en/mysqli-stmt.close.php
*/
$statementClosed = mysqli_stmt_close($statement);
if (!$statementClosed) {
throw new Exception('The prepared statement could not be closed!');
}
return $fetchedData;
}
<?php
/**
* Toggle error reporting.
*
* @param integer $level Error level.
* @param bool $displayErrors Display errors if TRUE, hide them otherwise.
* @return void
*/
function activateErrorReporting($level = E_ALL, $displayErrors = TRUE) {
error_reporting($level);
ini_set('display_errors', ($displayErrors ? 1 : 0));
}
/**
* Create a new db connection.
*
* @see http://php.net/manual/en/mysqli.construct.php
* @param string $host Host.
* @param string $dbname Database name.
* @param string $username Username.
* @param string $password Password.
* @param string $port [optional] Port.
* @return mysqli Db connection.
* @throws mysqli_sql_exception
*/
function createConnection($host, $dbname, $username, $password, $port = '3306') {
$connection = new mysqli($host, $username, $password, $dbname, $port);
if ($connection->connect_error) {
throw new Exception('Connect error: ' . $connection->connect_errno . ' - ' . $connection->connect_error);
}
return $connection;
}
/**
* Close db connection.
*
* @param mysqli $connection Connection instance.
* @return void
* @throws Exception
*/
function closeConnection($connection) {
$connectionClosed = $connection->close();
if (!$connectionClosed) {
throw new Exception('The db connection could not be closed!');
}
}
/**
* Fetch categories by parent.
*
* @param mysqli $connection Connection instance.
* @param integer $parent Parent.
* @return array Categories list.
* @throws Exception
*/
function fetchCategoriesByParent($connection, $parent) {
$fetchedData = array();
/*
* The SQL statement to be prepared. Notice the so-called markers,
* e.g. the "?" signs. They will be replaced later with the
* corresponding values when using mysqli_stmt::bind_param.
*
* See: http://php.net/manual/en/mysqli.prepare.php
*/
$sql = 'SELECT * FROM categories WHERE parent = ?';
/*
* Prepare the SQL statement for execution.
*
* Throws mysqli_sql_exception.
* See: http://php.net/manual/en/mysqli.prepare.php
*/
$statement = $connection->prepare($sql);
if (!$statement) {
throw new Exception('Prepare error: ' . $connection->errno . ' - ' . $connection->error);
}
/*
* Bind variables for the parameter markers (?) in the
* SQL statement that was passed to mysqli::prepare. The first
* argument of mysqli_stmt::bind_param is a string that contains one
* or more characters which specify the types for the corresponding bind variables.
*
* See: http://php.net/manual/en/mysqli-stmt.bind-param.php
*/
$bound = $statement->bind_param('i', $parent);
if (!$bound) {
throw new Exception('Bind error: The variables could not be bound to the prepared statement');
}
/*
* Execute the prepared SQL statement.
* When executed any parameter markers which exist will
* automatically be replaced with the appropriate data.
*
* See: http://php.net/manual/en/mysqli-stmt.execute.php
*/
$executed = $statement->execute();
if (!$executed) {
throw new Exception('Execute error: The prepared statement could not be executed!');
}
/*
* Get the result set from the prepared statement. In case of
* failure use errno, error and/or error_list to see the error.
*
* NOTA BENE:
* Available only with mysqlnd ("MySQL Native Driver")! If this
* is not installed, then uncomment "extension=php_mysqli_mysqlnd.dll" in
* PHP config file (php.ini) and restart web server (I assume Apache) and
* mysql service. Or use the following functions instead:
* mysqli_stmt::store_result + mysqli_stmt::bind_result + mysqli_stmt::fetch.
*
* See:
* http://php.net/manual/en/mysqli-stmt.get-result.php
* https://stackoverflow.com/questions/8321096/call-to-undefined-method-mysqli-stmtget-result
*/
$result = $statement->get_result();
if (!isset($result) || !$result) {
throw new Exception('Get result error: ' . $connection->errno . ' - ' . $connection->error);
}
/*
* Get the number of rows in the result.
*
* See: http://php.net/manual/en/mysqli-result.num-rows.php
*/
$numberOfRows = $result->num_rows;
/*
* Fetch data and save it into $fetchedData array.
*
* See: http://php.net/manual/en/mysqli-result.fetch-array.php
*/
if ($numberOfRows > 0) {
// Fetch all rows at once.
$fetchedData = $result->fetch_all(MYSQLI_ASSOC);
// ...or fetch one row at a time.
// while ($row = $result->fetch_array(MYSQLI_ASSOC)) {
// $fetchedData[] = $row;
// }
}
/*
* Free the memory associated with the result. You should
* always free your result when it is not needed anymore.
*
* See: http://php.net/manual/en/mysqli-result.free.php
*/
$result->close();
/*
* Close the prepared statement. It also deallocates the statement handle.
* If the statement has pending or unread results, it cancels them
* so that the next query can be executed.
*
* See: http://php.net/manual/en/mysqli-stmt.close.php
*/
$statementClosed = $statement->close();
if (!$statementClosed) {
throw new Exception('The prepared statement could not be closed!');
}
return $fetchedData;
}