docs(10_Wiki): Dev 폴더 누락분 반영 — Topic_Programming으로 통합

이전 재구성 작업에서 Dev/ 폴더가 누락되었던 것을 반영.

- Dev/Topic_Programming(중첩 폴더, 78개)은 Dev 자체 최상위 폴더들
  (Architecture/Conventions/Engineering_Intelligence 등)과 완전 중복이라 제거.
- Dev 최상위 엔지니어링 지식 폴더(Architecture/Conventions/Engineering_Intelligence/
  Failure_Library/Generalized_Principles/Language/Pattern_Catalog/Platform_Guides/
  Subsystems, 77개)는 이미 Topic_Programming/Topic_Programming에 더 최신 버전이
  존재해 중복 제거(고유 콘텐츠 1개는 예외 처리하여 이동 보존).
- Dev의 W3Schools 언어 튜토리얼 폴더(Topic_C/CPP/CSS/CSharp/HOWTO/HTML/Java/
  JavaScript/PHP/Python/SQL/W3CSS, 1201개)는 전부 Topic_Programming 하위로 이동.
- 에이전트 운영 상태(.astra/docs)는 그대로 유지, 콘텐츠 폴더만 정리.
- Topic_Programming 최종 문서 수: 2784 → 3985.

10_Wiki/Topic_Programming/Topic_PHP/PHP_AJAX_Database.md

@@ -0,0 +1,74 @@
+---
+id: php-ajax-database
+title: "PHP AJAX Database"
+category: "Programming_Language"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["AJAX MySQL", "PHP AJAX 데이터베이스"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.87
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["php", "programming", "w3schools", "ajax", "mysql"]
+raw_sources: ["https://www.w3schools.com/php/php_ajax_database.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[PHP AJAX Database]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+This chapter is the exact same AJAX architecture as the name-autocomplete example, but with the PHP endpoint querying a REAL MySQL database instead of a hardcoded array — the JS-side `showUser()` function and event-handling boilerplate barely change, proving the AJAX pattern is agnostic to where the PHP script actually gets its data. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **`onchange` event** (vs. `onkeyup` in the earlier example) — triggers on dropdown selection instead of every keystroke. [S1]
+- **Same AJAX skeleton** — `XMLHttpRequest` + `onreadystatechange` + query-string parameter passing, identical to the previous chapter. [S1]
+- **PHP-side database query** — `intval($_GET['q'])` sanitizes the ID as an integer, then a `SELECT * FROM user WHERE id = '$q'` query runs against MySQLi. [S1]
+- **Response is a rendered HTML table** — the PHP script builds `<table>` markup directly from the query results and echoes it, which JavaScript injects wholesale into the placeholder div. [S1]
+
+## 📖 세부 내용 (Details)
+- Dropdown trigger: `<select name="users" onchange="showUser(this.value)">`. [S1]
+- PHP query and HTML table generation: `$q = intval($_GET['q']); $con = mysqli_connect('localhost','peter','abc123'); mysqli_select_db($con,"ajax_demo"); $sql="SELECT * FROM user WHERE id = '".$q."'"; $result = mysqli_query($con,$sql); echo "<table>..."; while($row = mysqli_fetch_array($result)) { echo "<tr><td>" . $row['FirstName'] . "</td>...</tr>"; } echo "</table>";`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+소스에서 모순되는 정보는 발견되지 않음.
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — 드롭다운에서 인물을 선택하면 MySQL에서 정보를 조회해 테이블로 보여주는 것이 AJAX-DB 연동의 대표 실전 사례다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+PHP endpoint querying MySQL and returning an HTML table for AJAX (PHP):
+```php
+$q = intval($_GET['q']);
+$con = mysqli_connect('localhost', 'peter', 'abc123');
+mysqli_select_db($con, "ajax_demo");
+$sql = "SELECT * FROM user WHERE id = '" . $q . "'";
+$result = mysqli_query($con, $sql);
+echo "<table>...";
+while ($row = mysqli_fetch_array($result)) {
+    echo "<tr><td>" . $row['FirstName'] . "</td></tr>";
+}
+echo "</table>";
+```
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual
+- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
+- **신뢰 점수:** 0.87
+- **중복 검사 결과:** 신규 생성 (New discovery)
+
+## 🔗 지식 그래프 (Knowledge Graph)
+- **상위/루트:** [[PHP Tutorial]]
+- **관련 개념:** [[PHP AJAX PHP]], [[PHP MySQL Select]], [[PHP AJAX XML]]
+- **참조 맥락:** AJAX+MySQL 연동 — XML 데이터 연동(AJAX XML) 챕터로 이어짐.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — PHP - AJAX and MySQL — https://www.w3schools.com/php/php_ajax_database.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "PHP - AJAX and MySQL" page (Astra wiki-curation, P-Reinforce v3.1 format).