键列

• However , you can enter a null in the foreign - key column
  但是，可以在外键列中输入空值。
• Cannot be specified as key columns for an index
  的列指定为索引的键列。
• If one or more primary key columns are returned by the
  返回一个或多个主键列，则它们被用作
• You then relate the primary key column to a matching column
  然后需要将主键列与匹配列相关。
• This surrogate column can be designated the primary key column
  可以将该代理列指定为主键列。
• This is because the nonkey columns have the following benefits
  这是因为非键列具有下列优点：
• Provides a list of keyboard shortcuts for team explorer
  提供团队资源管理器的键盘快捷键列表。
• Restrict your choice of full - text key columns to a small column
  仅选择较小的列作为全文键列。
• The delete statement is provided all primary key column values
  为delete语句提供所有主键列值。
• Table matches the primary key column of the
  表中的主键列相对应。