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。
calculus of relations 关系演算
数据库 数据库理论 释文 relational calculus 关系演算
- two-stage programming
- two stage program with recourse
- two-stage sampling
- two-stage sampling inspection
- two stages dewatering process
- Two Stage Sisters
- two-stage stochastic programming
- two stage system
- two state system
- two-state system
- two-step acceleration
- two-step extraction procedure
- two-step flow of communication theory
- two-step growth method
- Two-Step Interactive Activation Theory
- two step mining
- two-step normalizing
- two steps heating
- two stream hypothesis
- two-stream instability
- two-stringed Chinese fiddle
- two stroke internal combustion engine
- Two Sworn Brothers
- two tailed test
- two-tailed test