Why Using POST for Updates Is Safer Than Hyperlinks

When updating a record in PHP, the choice between using Perform Actions (typically via forms and HTTP methods like POST or PUT) versus Hyperlinks (which generally use the GET method) boils down to security and best practices. Here’s why Perform Actions is preferred:

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Security

• GET (Hyperlinks): Actions triggered by links typically use the GET HTTP method, which is designed for retrieving information, not modifying it. When used for updates or deletions, sensitive data (such as the record ID) can be exposed in the URL, making it vulnerable to attacks like URL manipulation or CSRF (Cross-Site Request Forgery).

Problematic example:

<a href="update.php?id=123">Update</a>

Anyone could manipulate the id in the URL to tamper with unauthorized records.

• POST (Perform Actions): Updates should use a form with the POST method, where data is sent in the request body rather than the URL. This approach hides sensitive information and makes unauthorized manipulation more difficult, especially when combined with additional security measures like CSRF tokens.

Recommended example:

<form action="update.php" method="POST">
    <input type="hidden" name="id" value="123">
    <button type="submit">Update</button>
</form>

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Adhering to HTTP Conventions

The HTTP protocol has clear intentions for each method:

• GET: Retrieves information (idempotent and without side effects).
• POST/PUT: Submits or updates information (non-idempotent and with side effects).

Using GET for actions like updates or deletions violates these conventions and can confuse intermediaries like caches or proxies, which may treat GET requests as safe and side-effect-free.

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Preventing Unintended Actions

• Hyperlinks can be triggered unintentionally (e.g., accidental clicks or bots following the link).
• A form using POST, especially with an added confirmation step, reduces the likelihood of accidental execution.

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Compatibility with Advanced Security and Validation

Using forms allows for seamless integration of additional security measures, such as:

1. CSRF Tokens: Prevent malicious cross-origin requests.
2. Input Validation: Validate the record ID before submitting the form.
3. Permission Control: Verify user access rights before rendering the form.

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Using Perform Actions (via forms with POST or PUT) for updating records is the recommended approach. This ensures better security, aligns with HTTP conventions, and reduces the risk of accidental actions. Hyperlinks should be reserved for navigation or read-only actions that don’t alter the system's state.

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