Selecting from an external table reads the data from the data file(s) and provides it in the form of rows and columns as if it was read from the normal base table.

从外部表选择可从一个或多个数据文件读取数据，并以行和列的形式提供该数据，就好像从常规基表读取数据一样。

youdao

To load data from the data file /data/americascust.dat (created above) into the base table customer, use the INSERT statement as follows

要将数据文件 /data/americascust.dat（此前已创建）中的数据加载到基表 customer，可以使用 INSERT 语句（如下所示）

youdao

You can define a base set of tags for whatever your application needs, and then allow customers to add their own data into the file, in their own namespace, without disturbing your tree.

您可以定义您应用程序所需要的一组标签，然后允许客户将他们自己的数据以自己的命名空间添加到文件中，而不破坏您的节点树。

youdao