What are some common issues with WHERE clauses in SQL statements when using PHP?

One common issue with WHERE clauses in SQL statements when using PHP is not properly escaping user input, which can lead to SQL injection attacks. To solve this issue, you should always use prepared statements with parameterized queries to safely handle user input. 

// Example of using prepared statements with parameterized queries to prevent SQL injection

// Assuming $conn is a valid database connection

// User input
$user_input = $_POST['user_input'];

// Prepare a SQL statement with a placeholder for the user input
$stmt = $conn->prepare("SELECT * FROM users WHERE username = ?");

// Bind the user input to the placeholder
$stmt->bind_param("s", $user_input);

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

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

// Process the results
while ($row = $result->fetch_assoc()) {
    // Do something with the data
}

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

Keywords

SQL WHERE clause PHP error handling debugging

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