If there is no primary key, the first column that is not a long field is used.

如果没有主键，就会使用非长型字段的首列。

youdao

This is really useful when very long field names (such as those used with SAP) are in use.

当使用非常长的字段名称（例如 SAP 所使用的那些字段名称）时，这的确很有用。

youdao

But if you go back, 20 years ago or 25 years ago, it didn't really exist in Stanford long field.

但如果你往回想，20年或者25年前，在斯坦福中确实没有人对此进行研究。

youdao

It was mostly his military skill and intelligence that kept the South in the field so long.

VOA: special.2009.12.24

It settles into a long, powerless slide toward the landing field at Edwards Air Force Base.

VOA: special.2010.07.07

They form in long lines across the dune field.

VOA: special.2010.01.04

As they get ready to begin their defense, Enron's former chiefs are looking down a long field of play.

FORBES: The Enron Trial

Lay, Skilling and their attorneys are indeed starting from their own one-yard line and looking down a long field of play.

FORBES: Game On For Lay, Skilling

The rest of this long field is made up of the English Democrats, a Trade Union Socialist, another independent and someone calling himself Clint Bristow, who has not described himself as anything on the official nomination papers.

BBC: Rotherham by-election: Do independents have a prayer?