2nd/10_Wiki/Dev/Topic_SQL/SQL_Intro.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
sql-intro	SQL Intro	Database	draft	conceptual		SQL Introduction What is SQL SQL 소개 Structured Query Language		B	0.9	2026-07-04	2026-07-04			sql database w3schools rdbms basics	https://www.w3schools.com/sql/sql_intro.asp

SQL Intro

🎯 한 줄 통찰 (One-line insight)

SQL is the ANSI/ISO-standard language for accessing and manipulating data in a Relational Database Management System (RDBMS), where data lives in tables made of rows and columns. [S1]

🧠 핵심 개념 (Core concepts)

• SQL (Structured Query Language) — a standard language for accessing and manipulating databases, standardized by ANSI (1986) and ISO (1987). [S1]
• What SQL can do — execute queries, retrieve/insert/update/delete records, create databases/tables/stored procedures/views, and set permissions on tables, procedures, and views. [S1]
• Standard but fragmented — although SQL is an ANSI/ISO standard, different database systems implement their own proprietary extensions on top of a common core (SELECT/UPDATE/DELETE/INSERT/WHERE). [S1]
• RDBMS (Relational Database Management System) — the basis for SQL and all modern database systems (MS SQL Server, IBM DB2, Oracle, MySQL, MS Access); data is stored in tables, where a column is a vertical entity and a record (row) is a horizontal entity. [S1]
• Using SQL on a web site — typically requires an RDBMS program (MS Access/SQL Server/MySQL), a server-side scripting language (PHP/ASP) to run SQL, and HTML/CSS to present the results. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Table = columns + rows — every RDBMS models data as tables where columns define the schema and records (rows) hold the data. [S1]
• Standard-core + vendor-extension — expect the major commands to work everywhere, but expect proprietary extensions to differ per vendor. [S1]
• Three-layer web stack — RDBMS (data) + server-side language (logic) + HTML/CSS (presentation) is the classic pattern for a database-backed web site. [S1]

📖 세부 내용 (Details)

• SQL stands for Structured Query Language and lets you access and manipulate data stored in a database. [S1]
• It became a standard of the American National Standards Institute (ANSI) in 1986 and of the International Organization for Standardization (ISO) in 1987. [S1]
• Example table ("Customers") illustrates the RDBMS model:

SELECT * FROM Customers;

• The Customers example table has columns CustomerID, CustomerName, ContactName, Address, City, PostalCode, Country, and each row is one customer record. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 이 문서는 개론(Intro) 페이지로, 이후 SQL 튜토리얼 전체(SELECT/WHERE/JOIN 등)에서 여기서 정의한 RDBMS/테이블 모델이 반복 적용된다. [S1]

💻 코드 패턴 (Code patterns)

Select all records from a table (SQL):

SELECT * FROM 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: 0.90
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: SQL Tutorial
• 관련 개념: SQL Syntax, SQL Select, SQL Create Table
• 참조 맥락: SQL 튜토리얼 전체의 진입점 — RDBMS/테이블 모델을 처음 정의하는 문서.

📚 출처 (Sources)

• [S1] W3Schools — SQL Intro — https://www.w3schools.com/sql/sql_intro.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "SQL Intro" page (Astra wiki-curation, P-Reinforce v3.1 format).