Validate search parameters, use prepared statement parameters for user values and allowlist sortable SQL identifiers. The examples below demonstrate the main workflow, an edge case and one practical integration pattern.
What Does This Workflow Do?
Use the first example to see the core idea. The additional examples demonstrate validation and a separate integration scenario. Keep user values in prepared statement parameters, and allowlist SQL identifiers such as column names.
Syntax:
The complete workflow is demonstrated below; individual calls are explained in context.
Requirements and Data Flow
There is no single function signature for this workflow. The required variables depend on the request, server configuration and libraries used in the examples.
Example 1: Basic Usage
Validate search parameters, use prepared statement parameters for user values and allowlist sortable SQL identifiers.
<?php
$searchTerm = trim((string) ($_GET["search"] ?? ""));
$pdo = new PDO("sqlite::memory:");
$pdo->exec("CREATE TABLE articles (title TEXT)");
$statement = $pdo->prepare("SELECT title FROM articles WHERE title LIKE :query");
$statement->execute(["query" => "%" . $searchTerm . "%"]);
$results = $statement->fetchAll(PDO::FETCH_ASSOC);
This example demonstrates the central operation. The final output depends on the supplied input and, where relevant, the runtime or connected service.
Example 2: Handling a Different Case
<?php
$rawPage = "invalid";
$pageNumber = filter_var($rawPage, FILTER_VALIDATE_INT);
var_dump($pageNumber);
The second example focuses on a different input or failure condition, so the behavior can be distinguished from the basic case.
Practical Example
<?php
http_response_code(422);
header("Content-Type: application/problem+json");
echo json_encode(["type" => "about:blank", "title" => "Invalid request", "status" => 422], JSON_THROW_ON_ERROR);
The practical example demonstrates how the same subject fits into a larger application. Use your own file paths, endpoints and validated inputs rather than copying sample settings directly.
Important Behavior and Edge Cases
- Keep user values in prepared statement parameters, and allowlist SQL identifiers such as column names.
- Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
- Use the documented return type and handle false, null and exceptions according to the specific call.
Comparison With Related Functions
| Approach | Difference |
|---|---|
| Building a PHP Search Form with Database Filters | Validate search parameters, use prepared statement parameters for user values and allowlist sortable SQL identifiers. |
| PHP built-in functions | Solve individual low-level operations rather than complete workflows. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Ignoring errors from Building a PHP Search Form with Database Filters | Check the actual result and handle the expected error path. |
| Using the demonstration unchanged in production | Adapt file paths, configuration, authentication and permission rules to the application. |
| Treating input or returned data as trusted | Apply validation at input boundaries and context-aware escaping at output boundaries. |
Key Takeaways
- Keep user values in prepared statement parameters, and allowlist SQL identifiers such as column names.
- Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
- Use the documented return type and handle false, null and exceptions according to the specific call.
Validate search parameters, use prepared statement parameters for user values and allowlist sortable SQL identifiers. Use this approach when its capabilities and constraints match the application. Handle invalid data, failure conditions and resource cleanup explicitly.