You saw in Part 1, Figure 13 that the cn attribute type has a field called substr, which defines the matching rules for substring match.

在第1部分的图13可以看到，cn属性类型有一个叫做SUBSTR的字段，它定义了子字符串匹配的匹配规则。

youdao

You need to search for a substring, and return either the starting position of the match or the matching value itself.

你想搜索一个字符串，获取该子字符串匹配的起始位置或匹配值。

youdao

The search performs a partial match starting from the beginning of the text, and returning the first item in the list that matches the specified substring.

搜索执行从文本开始处开始的部分匹配，返回列表中第一个与指定的子字符串匹配的项。

youdao