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
- cyclooxygenase
- cyclo-oxygenase (COX)
- Cyclopedia of Education
- cyclopentadiene
- cyclopentadiene poisoning
- cyclopentadienyl (acetocyclopentadienyl) iron
- cyclopentadienyl hydridozirconium chloride
- cyclopentadienylindium
- cyclopentadienyl iron
- cyclopentadienyl metal
- cyclopentadienyltricarbonmonoxide manganese
- cyclopentane
- cyclopentanol
- cyclopentene
- cyclopeptide
- cyclophane
- cyclophosphamide DNA crosslinking reagent
- cyclophysis
- cyclopolycondensation
- cyclopolymerization
- cyclopropanation
- cyclopropane
- Cyclops project
- cyclorama light
- cyclorectifier