2nd/10_Wiki/Dev/Topic_SQL/SQL_Select_Into.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-select-into	SQL Select Into	Database	draft	conceptual		SQL SELECT INTO Statement SELECT INTO SQL 테이블 복사		B	0.88	2026-07-04	2026-07-04			sql database w3schools selectinto backup	https://www.w3schools.com/sql/sql_select_into.asp

SQL Select Into

🎯 한 줄 통찰 (One-line insight)

SELECT INTO creates a brand-new table populated from an existing one — useful for backups or ad-hoc analysis tables — but does not carry over primary keys, indexes, or NOT NULL constraints. [S1]

🧠 핵심 개념 (Core concepts)

• SELECT INTO statement — creates a new table and fills it with data from an existing table. [S1]
• Constraint loss — the new table gets the same column names/types as the source, but NOT primary keys, indexes, or NOT NULL constraints. [S1]
• Syntax (full copy) — SELECT * INTO newtable [IN external_db] FROM sourcetable WHERE condition;. [S1]
• Syntax (partial copy) — SELECT column1, column2, ... INTO newtable [IN external_db] FROM sourcetable WHERE condition;. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Empty-schema-clone trick — SELECT * INTO newtable FROM sourcetable WHERE 1 = 0; creates a new, empty table with the source's schema, by using a condition that structurally can never be true. [S1]
• Multi-table copy — SELECT INTO can source from a JOIN across multiple tables, not just a single table. [S1]

📖 세부 내용 (Details)

• Full backup copy: SELECT * INTO CustomersBackup2026 FROM Customers;. [S1]
• Backup into another database: SELECT * INTO CustomersBackup2026 IN 'Backup.mdb' FROM Customers;. [S1]
• Copy specific columns only: SELECT CustomerName, ContactName INTO Customers2 FROM Customers;. [S1]
• Copy a filtered subset: SELECT * INTO US_Customers FROM Customers WHERE Country = 'USA';. [S1]
• Copy from a JOIN: SELECT Customers.CustomerName, Orders.OrderID INTO CustomersOrder FROM Customers LEFT JOIN Orders ON Customers.CustomerID = Orders.CustomerID;. [S1]
• Empty schema-only clone: SELECT * INTO newtable FROM sourcetable WHERE 1 = 0;. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음. 다만 새 테이블이 원본의 제약조건(PK/인덱스/NOT NULL)을 물려받지 않는다는 한계가 명시적으로 언급됨. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 백업 테이블 생성, 분석용 임시 테이블 생성에 전형적으로 쓰인다. [S1]

💻 코드 패턴 (Code patterns)

Backup copy of a table (SQL):

SELECT * INTO CustomersBackup2026
FROM Customers;

Schema-only empty clone (SQL):

SELECT * INTO newtable
FROM sourcetable
WHERE 1 = 0;

✅ 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 Insert Into Select, SQL Create Table, SQL Left Join
• 참조 맥락: 새 테이블을 만들며 데이터를 채워야 할 때 사용 — 기존 테이블에 데이터만 옮기려면 대신 INSERT INTO SELECT를 사용.

📚 출처 (Sources)

• [S1] W3Schools — SQL SELECT INTO Statement — https://www.w3schools.com/sql/sql_select_into.asp

📝 변경 이력 (Change history)

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