这个键组合了多列，唯一地定义一个数据库表的行。

This is a key that combines a number of columns to uniquely define the rows of a database table.

youdao

清单12给出了多对多表的名称—即dw _ books_authors—以及该表中图书ISBN的键。

Listing 12 shows how to indicate the name of the many-to-many table-in this case, dw_books_authors-as well as the key for the book's ISBN in that same table.

youdao

在过去5年多的时间内，Ruby的一键式安装器已经有500多万的下载量了，不可思议吧。

The One-Click Installers for Ruby have been downloaded over 5 million times over the last 5+ years. Incredible.

youdao

The center of excess negative charge on all of the dipoles is at the very center of the molecule.

多出来的键,的负电荷中心都集中在,分子的正中间。

麻省理工公开课 - 固态化学导论课程节选