---
id: sql-avg
title: "SQL Avg"
category: "Database"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["SQL AVG() Function", "AVG function", "SQL 평균"]
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", "avg", "aggregate"]
raw_sources: ["https://www.w3schools.com/sql/sql_avg.asp"]
applied_in: []
github_commit: ""
---

# [[SQL Avg]]

## 🎯 한 줄 통찰 (One-line insight)
AVG() returns a numeric column's mean, ignoring NULLs, and doubles as a comparison baseline when nested as a subquery in a WHERE clause. [S1]

## 🧠 핵심 개념 (Core concepts)
- **AVG() function** — returns the average value of a numeric column; ignores NULL values. [S1]
- **Syntax** — `SELECT AVG(column_name) FROM table_name WHERE condition;`. [S1]
- **AVG() with GROUP BY** — returns the average per group. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **AVG() as a subquery baseline** — `WHERE Price > (SELECT AVG(Price) FROM Products)` uses AVG() inside a subquery to compare each row against the overall average — a reusable pattern for "above/below average" filters. [S1]

## 📖 세부 내용 (Details)
- Basic average: `SELECT AVG(Price) FROM Products;`. [S1]
- With WHERE: `SELECT AVG(Price) FROM Products WHERE CategoryID = 1;`. [S1]
- With alias: `SELECT AVG(Price) AS [average price] FROM Products;`. [S1]
- Above-average filter via subquery: `SELECT * FROM Products WHERE Price > (SELECT AVG(Price) FROM Products);`. [S1]
- With GROUP BY: `SELECT AVG(Price) AS AveragePrice, 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 — "평균 이상/이하" 필터링은 실무 리포트에서 흔한 패턴이다. [S1]

## 💻 코드 패턴 (Code patterns)
Above-average filter using AVG() as subquery (SQL):
```sql
SELECT * FROM Products
WHERE Price > (SELECT AVG(Price) FROM Products);
```

## ✅ 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 Group By]], [[SQL Where]]
- **참조 맥락:** 평균값 계산 및 평균 대비 비교 필터링의 기본 함수.

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

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