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
- personal selling
- personal software process
- personal software process, PSP
- Personal space
- personal space
- personal stereo
- personal striving
- personal study bibliography
- personal unconscious
- Person and Reality: An Introduction to Metaphysics
- Personas
- Persona satellite
- person centered therapy
- person-environment fit theory
- person identification
- personified exchange
- person in charge of an administrative organ
- person-in-situation
- person-job fit
- personlized instruction
- Personnel
- personnel archives of Tang Dynasty
- personnel assignment problem
- personnel control
- personnel dispute