unary relation and binary relation
2) Tuple 元组 3) Unary relation and Binary relation 单元关系与二 Relation is a two-dimension table, and every row corresponds a tuple, and every column corresponds a domain.
基于2个网页-相关网页
unary relation and binary relation
一元关系和二元关系
以上为机器翻译结果，长、整句建议使用 人工翻译 。