理学 数据库系统 释 relational calculus 关系演算 一种抽象的关系数据语言，它通过数理逻辑中的谓词演算表达查询的要求。
数据库 数据库理论 释文 relational calculus 关系演算
- Wigner rotation
- Wigner's distribution function
- Wigner-Seitz boundary condition
- Wigner-Seitz cell
- Wigner-Seitz theory
- Wigner-Seitz unit cell
- Wigner semicircle law
- Wigner theorem
- Wigner threshold law
- Wigner Weyl distribution function
- Wigner-Weyl distribution function
- Wigner-Weyl transform
- Wihwado Retreat
- Wijsman
- Wijsman convergence
- Wiki
- wiki
- Wikileaks
- Wikipedia
- Wikis as a Knowledge Management Tool
- Wiki作为知识管理工具
- Wik Judgement
- Wiktionary
- Wilbert Kumalija Chagula
- Wilbur Norman Christiansen