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
- Demoulin
- Demoulin quadrilateral
- Demoulin surface
- Demoulin tetrahedron
- Demoulin theorem
- demountable
- dempster shafer
- Dempster-Shafer evidential reasoning
- dempster-shafer theory
- Dempster-Shafer理论
- DEMS
- demulsification
- demulsifier
- de-multiplexer
- demultiplexer
- de-multiplexer, DEMUX
- de-multiplexing
- demultiplication
- De Muris
- demurrer
- DEMUX
- Demyan Bedny
- demyelination
- demyelinative diseases
- Demystified Southern School of Painting