refactor(topics): 멀티 에이전트용 지식 재편 — _Common(공통 기본기) + Domain_* 구조

에이전트 8종(대화형/프로그래머 C·S/디자이너/설계자/기획자/QA/PD/PM)에게
[공통 기본 능력 + 롤별 Specialty] 2층으로 지식을 주입하기 위한 재분류.
문서 내용·포맷은 무수정, 폴더 이동만 (6,372개 문서 수 보존 확인).

- Topic_Programming → Domain_Programming (내부 구조 보존)
- Topic_Graphic → Domain_Design
- Topic_Business → Domain_Product
- Topic_General → Domain_General
- _Common 신설: Math(구 Topic_Math_Specialty), Reasoning(구 General/From_Thinking & Reasoning),
  Reasoning_Creativity(구 General/From_창의성), Communication(Poetic_Blog_Writing + From_writing)
- 타 도메인의 From_* 폴더는 유지 (출처 표기일 뿐, 이미 도메인에 맞게 분류된 문서)
- 빈 폴더 정리 (memory/procedures)
- 에이전트→폴더 매핑은 workspace의 .astra/agent-knowledge-map.json (9개 에이전트)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

10_Wiki/Topics/Domain_Programming/Topic_SQL/SQL_Count.md

@@ -0,0 +1,75 @@
+---
+id: sql-count
+title: "SQL Count"
+category: "Database"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["SQL COUNT() Function", "COUNT function", "SQL 개수 세기"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.9
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["sql", "database", "w3schools", "count", "aggregate"]
+raw_sources: ["https://www.w3schools.com/sql/sql_count.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[SQL Count]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+COUNT() behaves differently depending on its argument — `COUNT(*)` counts all rows including NULLs, `COUNT(column)` counts non-null values, and `COUNT(DISTINCT column)` counts unique non-null values. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **COUNT() function** — returns the number of rows matching a specified criterion. [S1]
+- **Syntax** — `SELECT COUNT([DISTINCT] column_name | *) FROM table_name WHERE condition;`. [S1]
+- **`COUNT(*)`** — counts the total number of rows, including NULL values. [S1]
+- **`COUNT(column_name)`** — counts only non-null values in that column. [S1]
+- **`COUNT(DISTINCT column_name)`** — counts only unique, non-null values. [S1]
+
+## 🧩 추출된 패턴 (Extracted patterns)
+- **Argument choice changes semantics** — the three COUNT variants answer three different questions (total rows / filled-in rows / unique values), so picking the right one matters for correctness, not just style. [S1]
+
+## 📖 세부 내용 (Details)
+- Total row count: `SELECT COUNT(*) FROM Products;`. [S1]
+- Non-null count for a column: `SELECT COUNT(ProductName) FROM Products;`. [S1]
+- Unique non-null count: `SELECT COUNT(DISTINCT Price) FROM Products;`. [S1]
+- With WHERE: `SELECT COUNT(ProductID) FROM Products WHERE Price > 20;`. [S1]
+- With alias: `SELECT COUNT(*) AS [Number of records] FROM Products;`. [S1]
+- With GROUP BY: `SELECT COUNT(*) AS [Number of records], CategoryID FROM Products GROUP BY CategoryID;`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+소스에서 모순되는 정보는 발견되지 않음.
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — SELECT DISTINCT 챕터에서 이미 소개된 `COUNT(DISTINCT ...)` 패턴이 여기서 정식으로 다뤄진다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+Three COUNT variants (SQL):
+```sql
+SELECT COUNT(*) FROM Products;                 -- all rows, incl. NULLs
+SELECT COUNT(ProductName) FROM Products;       -- non-null values only
+SELECT COUNT(DISTINCT Price) FROM Products;    -- unique non-null values
+```
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual
+- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
+- **신뢰 점수:** 0.90
+- **중복 검사 결과:** 신규 생성 (New discovery)
+
+## 🔗 지식 그래프 (Knowledge Graph)
+- **상위/루트:** [[SQL Tutorial]]
+- **관련 개념:** [[SQL Aggregate Functions]], [[SQL Select Distinct]], [[SQL Group By]]
+- **참조 맥락:** 행 개수를 세는 모든 리포트의 기본 함수 — DISTINCT와 결합해 고유값 개수도 셀 수 있다.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — SQL COUNT() Function — https://www.w3schools.com/sql/sql_count.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "SQL COUNT() Function" page (Astra wiki-curation, P-Reinforce v3.1 format).