理学 数据库系统 释 relational algebra 关系代数 一种抽象的关系数据语言，它通过对关系的运算来表达查询。
algebra of relations 关系代数 relation algebra 关系代数 relational algebra 关系代数 relationship algebra 关系代数
数据库 数据库理论 释文 relational algebra 关系代数
- receptor antagonist
- receptor-based pharmacophore model
- receptor coding
- receptor desensitization
- receptor destroying enzyme
- receptorediting
- receptor genetic polymorphism
- receptor imaging
- receptor imaging agent
- receptor inactivation
- receptor internalization
- receptor inverse agonist
- receptor-like protein kinase
- receptor-mediated endocytosis
- receptor mediated gene transfer technology
- receptor-mediated targeting drug delivery systems
- receptor model
- receptor model method
- receptor organism
- receptor potential
- receptor protein
- receptor tyrosine kinase
- recess
- recessing
- recession