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＃Elasticsearch允许给文档建立父子关系，这篇博客介绍文档的父子关系是如何映射的(Parent-Child Mapping)、如何索引父子文档(Indexing Parents and Children)、如何通过子文档查询父文档
(Finding Parents by Their Children)、如何通过父文档查询子文档(Finding Children by Their Parents)。建立文档的父子关系最重要的一步是在创建索引的时候在mapping中声明哪个是父文档哪个是子文档。官网文档给了一个公司在很多城市的分支(branch)和每个分支有相关员工(employee)的例子，如果想把员工和他们工作的分公司关联起来，我们需要告诉Elasticsearch文档之间的父子关系，这里employee是child type,branch是parent type，在mapping中声明：
curl -XPUT "http://192.168.0.224:9200/company" -d '{ "mappings": { "branch": {}, "employee": { "_parent": { "type": "branch" } } }}' 这样我们创建了一个索引，并制定了2个type和它们之间的父子关系.
索引父文档和索引一般的文档没有任何区别。
准备几条公司的数据，存在company.json文件中：{ "index": { "_id": "london" }}{ "name": "London Westminster", "city": "London", "country": "UK" }{ "index": { "_id": "liverpool" }}{ "name": "Liverpool Central", "city": "Liverpool", "country": "UK" }{ "index": { "_id": "paris" }}{ "name": "Champs Élysées", "city": "Paris", "country": "France" } 使用Bulk端点批量导入：
curl -XPOST "http://192.168.0.224:9200/company/branch/_bulk?pretty" --data-binary @company.json
索引子文档需要制定子文档的父ID，给子文档的每条文档设置parent属性的value为父文档id即可：
curl -XPUT "http://192.168.0.224:9200/company/employee/1?parent=london&pretty" -d '{ "name": "Alice Smith", "dob": "1970-10-24", "hobby": "hiking"}' 上面的操作我们新增了一条数据，/company/employee/1的父文档为/company/branch/london。
同样可以批量索引子文档，把employee数据存入json文件中：{ "index": { "_id": 2, "parent": "london" }}{ "name": "Mark Thomas", "dob": "1982-05-16", "hobby": "diving" }{ "index": { "_id": 3, "parent": "liverpool" }}{ "name": "Barry Smith", "dob": "1979-04-01", "hobby": "hiking" }{ "index": { "_id": 4, "parent": "paris" }}{ "name": "Adrien Grand", "dob": "1987-05-11", "hobby": "horses" } 执行bulk命令：
curl -XPOST "http://192.168.0.224:9200/company/employee/_bulk?pretty" --data-binary @employee.json
搜索含有1980年以后出生的employee的branch：
curl -XGET "http://192.168.0.224:9200/company/branch/_search?pretty" -d '{ "query": { "has_child": { "type": "employee", "query": { "range": { "dob": { "gte": "1980-01-01" } } } } }}'{ "took" : 19, "timed_out" : false, "_shards" : { "total" : 5, "successful" : 5, "failed" : 0 }, "hits" : { "total" : 2, "max_score" : 1.0, "hits" : [ { "_index" : "company", "_type" : "branch", "_id" : "paris", "_score" : 1.0, "_source" : { "name" : "Champs Élysées", "city" : "Paris", "country" : "France" } }, { "_index" : "company", "_type" : "branch", "_id" : "london", "_score" : 1.0, "_source" : { "name" : "London Westminster", "city" : "London", "country" : "UK" } } ] }} 查询name中含有“Alice Smith”的branch:
curl -XGET "http://192.168.0.224:9200/company/branch/_search?pretty" -d '{ "query": { "has_child": { "type": "employee", "score_mode": "max", "query": { "match": { "name": "Alice Smith" } } } }}'{ "took" : 20, "timed_out" : false, "_shards" : { "total" : 5, "successful" : 5, "failed" : 0 }, "hits" : { "total" : 2, "max_score" : 1.2422675, "hits" : [ { "_index" : "company", "_type" : "branch", "_id" : "london", "_score" : 1.2422675, "_source" : { "name" : "London Westminster", "city" : "London", "country" : "UK" } }, { "_index" : "company", "_type" : "branch", "_id" : "liverpool", "_score" : 0.30617762, "_source" : { "name" : "Liverpool Central", "city" : "Liverpool", "country" : "UK" } } ] }} 搜索最少含有2个employee的branch：
curl -XGET "http://192.168.0.224:9200/company/branch/_search?pretty" -d '{"query": { "has_child": { "type": "employee", "min_children": 2, "query": { "match_all": {} } } }}'{ "took" : 17, "timed_out" : false, "_shards" : { "total" : 5, "successful" : 5, "failed" : 0 }, "hits" : { "total" : 1, "max_score" : 1.0, "hits" : [ { "_index" : "company", "_type" : "branch", "_id" : "london", "_score" : 1.0, "_source" : { "name" : "London Westminster", "city" : "London", "country" : "UK" } } ] }} 搜搜工作在UK的employee：
curl -XGET "http://192.168.0.224:9200/company/employee/_search?pretty" -d '{ "query": { "has_parent": { "type": "branch", "query": { "match": { "country": "UK" } } } }}'{ "took" : 15, "timed_out" : false, "_shards" : { "total" : 5, "successful" : 5, "failed" : 0 }, "hits" : { "total" : 3, "max_score" : 1.0, "hits" : [ { "_index" : "company", "_type" : "employee", "_id" : "3", "_score" : 1.0, "_parent" : "liverpool", "_routing" : "liverpool", "_source" : { "name" : "Barry Smith", "dob" : "1979-04-01", "hobby" : "hiking" } }, { "_index" : "company", "_type" : "employee", "_id" : "1", "_score" : 1.0, "_parent" : "london", "_routing" : "london", "_source" : { "name" : "Alice Smith", "dob" : "1970-10-24", "hobby" : "hiking" } }, { "_index" : "company", "_type" : "employee", "_id" : "2", "_score" : 1.0, "_parent" : "london", "_routing" : "london", "_source" : { "name" : "Mark Thomas", "dob" : "1982-05-16", "hobby" : "diving" } } ] }} 转载地址：http://dcjoo.baihongyu.com/