For example, the foreign key to the date table is not repeated for every keyword of a document.

例如，日期表的外键对于一个文档的每个关键词不会重复。

youdao

For example, the foreign key to the date table is not repeated for every keyword of a document.

例如，日期表的外键对于一个文档的每个关键词不会重复。

youdao