---
id: sql-having
title: "SQL Having"
category: "Database"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["SQL HAVING Clause", "HAVING clause", "SQL 그룹 조건절"]
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", "having", "groupby", "aggregate"]
raw_sources: ["https://www.w3schools.com/sql/sql_having.asp"]
applied_in: []
github_commit: ""
---

# [[SQL Having]]

## 🎯 한 줄 통찰 (One-line insight)
HAVING filters GROUP BY results based on aggregate conditions, applying AFTER grouping — unlike WHERE, which filters individual rows BEFORE grouping. [S1]

## 🧠 핵심 개념 (Core concepts)
- **HAVING clause** — filters the results of a GROUP BY query based on aggregate functions. [S1]
- **WHERE vs. HAVING** — WHERE filters individual rows before grouping; HAVING filters groups after aggregation. [S1]
- **Syntax** — `SELECT column1, aggregate_function(column2), column3, ... FROM table_name WHERE condition GROUP BY column1, column3 HAVING condition ORDER BY column_name;`. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **WHERE + GROUP BY + HAVING composition** — a query can filter rows first (WHERE), group them, then filter the resulting groups (HAVING) — e.g. restrict to two named employees, group by last name, then keep only groups with more than 25 orders. [S1]

## 📖 세부 내용 (Details)
- Countries with more than 5 customers: `SELECT Country, COUNT(CustomerID) AS [Number of Customers] FROM Customers GROUP BY Country HAVING COUNT(CustomerID) > 5;`. [S1]
- Same, sorted descending: `... GROUP BY Country HAVING COUNT(CustomerID) > 5 ORDER BY COUNT(CustomerID) DESC;`. [S1]
- Employees with more than 10 orders, via JOIN + GROUP BY + HAVING: `SELECT Employees.LastName, COUNT(Orders.OrderID) AS NumberOfOrders FROM Orders INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID GROUP BY LastName HAVING COUNT(Orders.OrderID) > 10;`. [S1]
- Combined WHERE + GROUP BY + HAVING: filter to two named employees first, then keep only those with more than 25 orders. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
소스에서 모순되는 정보는 발견되지 않음.

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — "N건 이상인 그룹만 보기" 같은 리포팅 쿼리에서 GROUP BY와 항상 짝을 이뤄 쓰인다. [S1]

## 💻 코드 패턴 (Code patterns)
Filter groups by aggregate condition (SQL):
```sql
SELECT Country, COUNT(CustomerID) AS [Number of Customers]
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;
```

## ✅ 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 Group By]], [[SQL Where]], [[SQL Aggregate Functions]]
- **참조 맥락:** GROUP BY 결과 자체를 조건으로 걸러야 할 때 사용 — WHERE와 역할을 혼동하지 않는 것이 핵심.

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

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