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
- James William Cooley
- James William Fulbright
- James William Toumey
- James Wilson Morrice
- James Wong Howe
- James Wright
- James Wynne Dungey
- Jamil Abu Sbaih
- Jamin interferometer
- Jamini Roy
- Jamin's interferometer
- jammer
- jamming
- jamming effect
- Jammu
- Jamnagar
- jamproof
- Jamshedpur
- Jamsil Olympic Stadium
- Jamuchi postal relay station
- Jamuqa
- Jamāl al-Din
- Jamāl al-Ghaytānī
- Janakpur
- Jan and Hubert van Eyck