What steps can be taken to troubleshoot and resolve issues with PHP database queries not returning results when special characters are involved?

When special characters are involved in PHP database queries, it's important to properly handle and sanitize the input to prevent SQL injection attacks. One common issue that may arise is when special characters are not properly escaped, leading to queries not returning results as expected. To resolve this, you can use prepared statements with parameterized queries to safely handle special characters in the database queries. 

// Establish a database connection
$mysqli = new mysqli("localhost", "username", "password", "database");

// Check for connection errors
if ($mysqli->connect_error) {
    die("Connection failed: " . $mysqli->connect_error);
}

// Prepare a SQL statement with a parameterized query
$stmt = $mysqli->prepare("SELECT * FROM table WHERE column = ?");
$stmt->bind_param("s", $search_term);

// Sanitize and set the search term with special characters
$search_term = mysqli_real_escape_string($mysqli, $search_term);

// Execute the query
$stmt->execute();

// Get the results
$result = $stmt->get_result();

// Loop through the results
while ($row = $result->fetch_assoc()) {
    // Output the results
    echo $row['column_name'];
}

// Close the statement and connection
$stmt->close();
$mysqli->close();

Keywords

PHP database queries special characters encoding troubleshooting

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