lucene 中 BooleanClause.Occur.Must 和 BooleanClause.Occur.SHOULD 之间的区别 [英] Difference between BooleanClause.Occur.Must and BooleanClause.Occur.SHOULD in lucene

问题描述

谁能举例说明 BooleanQuery 中 lucene 中 BooleanClause.Occur.Must 和 BooleanClause.Occur.SHOULD 的区别?

Can anyone explain the difference between the BooleanClause.Occur.Must and BooleanClause.Occur.SHOULD in lucene in BooleanQuery with an example?

推荐答案

BooleanClause.Occur.SHOULD 表示该子句是可选的，而 BooleanClause.Occur.Must 表示该条款是强制性的.

BooleanClause.Occur.SHOULD means that the clause is optional, whereas BooleanClause.Occur.Must means that the clause is compulsory.

但是，如果布尔查询只有可选子句，则必须至少匹配一个子句才能使文档出现在结果中.

However, if a boolean query only has optional clauses, at least one clause must match for a document to appear in the results.

为了更好地控制哪些文档与 BooleanQuery 匹配，还有一个 minimumShouldMatch 参数让您告诉 Lucene 至少 minimumShouldMatch BooleanClause.Occur.SHOULD 子句必须匹配，文档才会出现在结果中.

For better control over what documents match a BooleanQuery, there is also a minimumShouldMatch parameter which lets you tell Lucene that at least minimumShouldMatch BooleanClause.Occur.SHOULD clauses must match for a document to appear in the results.

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