Question: What is a subquery, and how is it different from a JOIN?Answer: A subquery is a query nested within another query, returning a single value or a set of values. JOIN combines rows from two or more tables based on a related column. |
복습용 저장
이 항목을 북마크하거나, 어렵게 표시하거나, 복습 세트에 넣을 수 있습니다.
도움이 되었나요? 예 아니요
Most helpful rated by users:
- Explain the concept of ACID properties in the context of databases.
- What is the purpose of the WHERE clause in a PostgreSQL query?
- What is a foreign key, and how does it enforce referential integrity?
- Explain the purpose of the SERIAL data type in PostgreSQL.