Merge pull request #45 from richardwei2008/p2_chapter13/15_Combining_queries

chapter13_part4: /100_Full_Text_Search/15_Combining_queries.asciidoc

Author: medcl

100_Full_Text_Search/15_Combining_queries.asciidoc

@@ -1,16 +1,11 @@
 [[bool-query]]
-=== Combining Queries
+=== 组合查询
 
-In <<combining-filters>> we discussed how to((("full text search", "combining queries"))), use the `bool` filter to combine
-multiple filter clauses with `and`, `or`, and `not` logic.  In query land, the
-`bool` query does a similar job but with one important difference.
+在 <<combining-filters,组合过滤器>> 中，我们讨论过如何使用 `bool` 过滤器通过 `and` 、 `or` 和 `not` 逻辑组合将多个过滤器进行组合。在查询中， `bool` 查询有类似的功能，只有一个重要的区别。
 
-Filters make a binary decision: should this document be included in the
-results list or not? Queries, however, are more subtle. They decide not only
-whether to include a document, but also how _relevant_ that document is.
+过滤器做二元判断：文档是否应该出现在结果中？但查询更精妙，它除了决定一个文档是否应该被包括在结果中，还会计算文档的 _相关程度_ 。
 
-Like the filter equivalent, the `bool` query accepts((("bool query"))) multiple query clauses
-under the `must`, `must_not`, and `should` parameters.  For instance:
+与过滤器一样， `bool` 查询也可以接受 `must` 、 `must_not` 和 `should` 参数下的多个查询语句。((("bool query")))比如：
 
 [source,js]
 --------------------------------------------------
@@ -30,13 +25,9 @@ GET /my_index/my_type/_search
 --------------------------------------------------
 // SENSE: 100_Full_Text_Search/15_Bool_query.json
 
-The results from the preceding query include any document whose `title` field
-contains the term `quick`, except for those that also contain `lazy`. So
-far, this is pretty similar to how the `bool` filter works.
+以上的查询结果返回 `title` 字段包含词项 `quick` 但不包含 `lazy` 的任意文档。目前为止，这与 `bool` 过滤器的工作方式非常相似。
 
-The difference comes in with the two `should` clauses, which say that: a document
-is _not required_ to contain ((("should clause", "in bool queries")))either `brown` or `dog`, but if it does, then
-it should be considered _more relevant_:
+区别就在于两个 `should` 语句，也就是说：一个文档不必包含((("should clause", "in bool queries"))) `brown` 或 `dog` 这两个词项，但如果一旦包含，我们就认为它们 _更相关_ ：
 
 [source,js]
 --------------------------------------------------
@@ -60,28 +51,19 @@ it should be considered _more relevant_:
 }
 --------------------------------------------------
 
-<1> Document 3 scores higher because it contains both `brown` and `dog`.
+<1> 文档 3 会比文档 1 有更高评分是因为它同时包含 `brown` 和 `dog` 。
 
-==== Score Calculation
+==== 评分计算
 
-The `bool` query calculates((("relevance scores", "calculation in bool queries")))((("bool query", "score calculation"))) the relevance `_score` for each document by adding
-together the `_score` from all of the matching `must` and `should` clauses,
-and then dividing by the total number of `must` and `should` clauses.
+`bool` 查询会为每个文档计算相关度评分 `_score` ，((("relevance scores", "calculation in bool queries")))((("bool query", "score calculation")))再将所有匹配的 `must` 和 `should` 语句的分数 `_score` 求和，最后除以 `must` 和 `should` 语句的总数。
 
-The `must_not` clauses do not affect ((("must_not clause", "in bool queries")))the score; their only purpose is to
-exclude documents that might otherwise have been included.
+`must_not` 语句不会影响评分；((("must_not clause", "in bool queries")))它的作用只是将不相关的文档排除。
 
-==== Controlling Precision
+==== 控制精度
 
-All the `must` clauses must match, and all the `must_not` clauses must not
-match, but how many `should` clauses((("bool query", "controlling precision")))((("full text search", "combining queries", "controlling precision")))((("precision", "controlling for bool query"))) should match? By default, none of the `should` clauses are required to match, with one
-exception: if there are no `must` clauses, then at least one `should` clause
-must match.
+所有 `must` 语句必须匹配，所有 `must_not` 语句都必须不匹配，但有多少 `should` 语句应该匹配呢？((("bool query", "controlling precision")))((("full text search", "combining queries", "controlling precision")))((("precision", "controlling for bool query")))默认情况下，没有 `should` 语句是必须匹配的，只有一个例外：那就是当没有 `must` 语句的时候，至少有一个 `should` 语句必须匹配。
 
-Just as we can control the <<match-precision,precision of the `match` query>>,
-we can control how many `should` clauses need to match by using the
-`minimum_should_match` parameter,((("minimum_should_match parameter", "in bool queries"))) either as an absolute number or as a
-percentage:
+就像我们能控制 <<match-precision, `match` 查询的精度>> 一样，我们可以通过 `minimum_should_match` 参数控制需要匹配的 `should` 语句的数量，((("minimum_should_match parameter", "in bool queries")))它既可以是一个绝对的数字，又可以是个百分比：
 
 [source,js]
 --------------------------------------------------
@@ -101,10 +83,7 @@ GET /my_index/my_type/_search
 --------------------------------------------------
 // SENSE: 100_Full_Text_Search/15_Bool_query.json
 
-<1> This could also be expressed as a percentage.
-
-The results would include only documents whose `title` field contains `"brown"
-AND "fox"`, `"brown" AND "dog"`, or `"fox" AND "dog"`. If a document contains
-all three, it would be considered more relevant than those that contain
-just two of the three.
+<1> 这也可以用百分比表示。
 
+这个查询结果会将所有满足以下条件的文档返回： `title` 字段包含 `"brown"
+AND "fox"` 、 `"brown" AND "dog"` 或 `"fox" AND "dog"` 。如果有文档包含所有三个条件，它会比只包含两个的文档更相关。