We focus on the research of querymodification by applying security constraints.
本文重点研究了多级安全环境下，利用约束处理来实现查询处理的方法。
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This section of the article will use several examples to demonstrate how querymodification can be implemented.
文章的这个部分，使用几个例子，解释了怎样操作自定义查询。
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The first step is to create a compatible regular expression out of each query word, although modification is only required if the word contains a wildcard character: *.