ES 中join的使用
引出问题
在mysql中，可以使用join来实现表与表之间的数据连接，在es中如何实现这个问题？
相对于mysql来说，es有几个不同的地方
- 不支持跨index的join
- 一个index只能包含一个类型
- 分布式的存储方式，对于数据的搜寻造成障碍
对于上面的几个问题，es的解决方案是**在一个索引下，借助父子关系，实现类似Mysql中多表关联的操作**
定义类型和join索引
PUT myorder
{
"mappings": {
"_doc": {
"properties": {
"order_join": {
"type": "join",
"relations": {
"order": "suborder"
}
}
}
}
}
}定义join关系为order_join,其中order是父文档，suborder是子文档。
put myorder/_mapping/_doc
{
"properties": {
"orderId": {
"type": "keyword"
},
"shortTime": {
"type": "date"
},
"name": {
"type": "keyword"
},
"amount": {
"type": "double"
},
"desc": {
"type": "text"
}
}
}插入主单数据
PUT myorder/_doc/10001
{
"shortTime": "2019-01-05",
"orderId": "10001",
"name": "user2",
"amount": 123.09,
"desc": "其他收入",
"order_join": "order"
}order_join定义为order类型
插入子单数据
使用自定义ID用PUT方法
POST myorder/_doc?routing=1
{
"shortTime": "2019-01-05",
"orderId": "10001",
"name": "user2",
"amount": 12.09,
"desc": "收入",
"order_join": {
"name": "suborder",
"parent":"10001"
}
}POST myorder/_doc?routing=1
{
"shortTime": "2019-01-05",
"orderId": "10002",
"name": "user2",
"amount": 122.09,
"desc": "收入",
"order_join": {
"name": "suborder",
"parent":"10001"
}
}建立父子关系索引，
routing参数是必须的，因为父子文档必须在同一个分片上
查询主单
GET myorder/_search
{
"query": {
"has_child" : {
"type" : "suborder",
"query" : {
"match_all" : {
}
}
}
}
}查询子单
GET myorder/_search
{
"query": {
"has_parent" : {
"parent_type" : "order",
"query" : {
"match_all" : {
}
}
}
}
}聚合查询
- 主单聚合
GET myorder/_search
{
"query": {
"parent_id": {
"type": "suborder",
"id": "10001"
}
},
"aggs": {
"parents12312": {
"terms": {
"field": "order_join#order"
},
"aggs": {
"sumAmount": {
"stats": {
"field": "amount"
}
}
}
}
}
}
- 子单聚合
GET myorder/_search
{
"size": 0,
"aggs": {
"parent": {
"children": {
"type": "suborder"
},
"aggs": {
"sumAmount": {
"stats": {
"field": "amount"
}
}
}
}
}
}
- 聚合加筛选：
GET myorder/_search
{
"query": {
"has_child" : {
"type" : "suborder",
"query" : {
"match_all" : {
}
}
}
},
"aggs": {
"parent": {
"children": {
"type": "suborder"
},
"aggs": {
"fields": {
"terms": {
"field": "orderId"
},
"aggs": {
"sumAmount": {
"sum": {
"field": "amount"
}
},
"having": {
"bucket_selector": {
"buckets_path": {
"orderCount": "_count",
"sumAmount": "sumAmount"
},
"script": {
"source": "params.sumAmount >= 100 && params.orderCount >=0"
}
}
}
}
}
}
}
}
} 定义一对多的索引
一对一的索引模型很难满足日常业务的数据处理，es也支持一对多的join
PUT myorder
{
"mappings": {
"_doc": {
"properties": {
"order_join": {
"type": "join",
"relations": {
"order": ["suborder1", "suborder2"],
"suborder2":"suborder3"
}
}
}
}
}
}上面的索引的关联的关系如下：
order
/ \
suborder1 suborder2
\
suborder3 本文参与 腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。
原始发表：2019-02-21 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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