理学 数据库系统设计 释 entity-relationship model 实体关系模型 通过客观事物及其联系进行形式化描述的数据模型。又称实体-联系模型、E-R模型。
数据库 数据库理论 释文 entity-relationship model 实体-联系模型
- semi-fir
- semi-fixed dune
- semi-fixed sandy land
- semi-flat
- semi flexible chain polymer
- semi-flexible chain polymer
- semi flexible docking
- semi-flexible docking
- semi-floating-gate transistor
- semi-floating mandrel mill
- semi flow
- semi-flow
- semifocal chord
- semi-forbidden line
- semiformal
- semiformal axiomatic system
- semiformal system
- semi fragile watermarking
- semi-fragile watermarking
- semi Fredholm operator
- semi-Fredholm operator
- semi-free
- semi-free group action
- semi-function
- semi-functional graph