---
id: sql-views
title: "SQL Views"
category: "Database"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["SQL CREATE VIEW Statement", "SQL View", "가상 테이블"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.88
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["sql", "database", "w3schools", "view"]
raw_sources: ["https://www.w3schools.com/sql/sql_view.asp"]
applied_in: []
github_commit: ""
---

# [[SQL Views]]

## 🎯 한 줄 통찰 (One-line insight)
A view is a virtual table backed only by a stored SELECT definition, not a data copy — so it always reflects real-time data, and updating it requires vendor-specific syntax (ALTER VIEW vs. CREATE OR REPLACE VIEW). [S1]

## 🧠 핵심 개념 (Core concepts)
- **SQL view** — a virtual table based on the result-set of an SQL statement; fields come from one or more real tables. [S1]
- **Always real-time** — the database only stores the view's SELECT definition, not a data copy, so querying a view always reflects current data. [S1]
- **Syntax (create)** — `CREATE VIEW view_name AS SELECT column1, column2, ... FROM table_name WHERE condition;`. [S1]
- **Querying a view** — `SELECT * FROM view_name;`, exactly like querying a real table. [S1]
- **Updating a view** — `ALTER VIEW` (SQL Server) vs. `CREATE OR REPLACE VIEW` (MySQL/Oracle). [S1]
- **Dropping a view** — `DROP VIEW view_name;`. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **View as a saved query with a table name** — a view can encapsulate a subquery-based filter (e.g. "products above average price") behind a simple table-like name, hiding the underlying complexity from downstream queries. [S1]

## 📖 세부 내용 (Details)
- Simple filtered view: `CREATE VIEW [Brazil Customers] AS SELECT CustomerName, ContactName FROM Customers WHERE Country = 'Brazil';`, queried as `SELECT * FROM [Brazil Customers];`. [S1]
- View wrapping a subquery: `CREATE VIEW [Products Above Average Price] AS SELECT ProductName, Price FROM Products WHERE Price > (SELECT AVG(Price) FROM Products);`. [S1]
- Update a view (SQL Server): `ALTER VIEW [Brazil Customers] AS SELECT CustomerName, ContactName, City FROM Customers WHERE Country = 'Brazil';`. [S1]
- Update a view (MySQL/Oracle): `CREATE OR REPLACE VIEW [Brazil Customers] AS SELECT CustomerName, ContactName, City FROM Customers WHERE Country = 'Brazil';`. [S1]
- Drop a view: `DROP VIEW [Brazil Customers];`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **뷰 갱신 문법이 벤더별로 다름**: SQL Server는 `ALTER VIEW`, MySQL/Oracle은 `CREATE OR REPLACE VIEW`를 사용. [S1]

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — AVG() 서브쿼리를 뷰로 감싸 재사용 가능한 이름으로 노출하는 예시가 소스에 직접 등장한다. [S1]

## 💻 코드 패턴 (Code patterns)
Create and query a view (SQL):
```sql
CREATE VIEW [Brazil Customers] AS
SELECT CustomerName, ContactName
FROM Customers
WHERE Country = 'Brazil';

SELECT * FROM [Brazil Customers];
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.88
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[SQL Tutorial]]
- **관련 개념:** [[SQL Select]], [[SQL Avg]], [[SQL Create Table]]
- **참조 맥락:** 복잡한 쿼리를 재사용 가능한 가상 테이블로 감싸야 할 때 사용.

## 📚 출처 (Sources)
- [S1] W3Schools — SQL Views — https://www.w3schools.com/sql/sql_view.asp

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "SQL Views" page (Astra wiki-curation, P-Reinforce v3.1 format).