若在传统DBMS 关系型数据库中查询海量数据,特别是模糊查询,一般我们都是使用like %查询的值%,但这样会导致无法应用索引,从而形成全表扫描效率低下,即使是在有索引的字段精确值查找,面对海量数据,效率也是相对较低的,所以
若在传统DBMS 关系型数据库中查询海量数据,特别是模糊查询,一般我们都是使用like %查询的值%,但这样会导致无法应用索引,从而形成全表扫描效率低下,即使是在有索引的字段精确值查找,面对海量数据,效率也是相对较低的,所以目前一般的互联网公司或大型公司,若要查询海量数据,最好的办法就是使用搜索引擎,目前比较主流的搜索引擎框架就是:elasticsearch,故今天我这里总结了Elasticsearch必知必会的干货知识一:ES索引文档的CRUD,后面陆续还会有其它干货知识分享,敬请期待。
ES索引文档的CRUD(6.X与7.X有区别,6.X中支持一个index创建多个type,而7.X中及以上只支持1个固定的type,即:_doc,api用法上也稍有不同):
Create创建索引文档【POST index/type/id可选,如果index、type、id已存在则重建索引文档(先删除后创建索引文档,与Put index/type/id 原理相同),如果在指定id情况下需要限制自动更新,则可以使用:index/type/id?op_type=create 或 index/type/id/_create,指明操作类型为创建,这样当存在的记录的情况下会报错】
POST demo_users/_doc 或 demo_users/_doc/2vJKsm8BriJODA6s9GbQ/_create
Request Body:
{
"userId":1,
"username":"张三",
"role":"administrator",
"enabled":true,
"createdDate":"2020-01-01T12:00:00"
}
Response Body:
{
"_index": "demo_users",
"_type": "_doc",
"_id": "2vJKsm8BriJODA6s9GbQ",
"_version": 1,
"result": "created",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 0,
"_primary_term": 1
}
Get获取索引文档【Get index/type/id】
Get demo_users/_doc/123
Response Body:
{
"_index": "demo_users",
"_type": "_doc",
"_id": "123",
"_version": 1,
"found": true,
"_source": {
"userId": 1,
"username": "张三",
"role": "administrator",
"enabled": true,
"createdDate": "2020-01-01T12:00:00"
}
}
Index Put重建索引文档【PUT index/type/id 或 index/type/id?op_type=index,id必传,如果id不存在文档则创建文档,否则先删除原有id文档后再重新创建文档,version加1】
Put/POST demo_users/_doc/123 或 demo_users/_doc/123?op_type=index
Request Body:
{
"userId":1,
"username":"张三",
"role":"administrator",
"enabled":true,
"createdDate":"2020-01-01T12:00:00",
"remark":"仅演示"
}
Response Body:
{
"_index": "demo_users",
"_type": "_doc",
"_id": "123",
"_version": 4,
"result": "updated",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 10,
"_primary_term": 1
}
Update更新索引文档【POST index/type/id/_update 请求体必需是{"doc":{具体的文档JSON}},如果指定的键字段已存在则更新,如果指定的键字段不存在则附加新的键值对,支持多层级嵌套,多次请求,如果有字段值有更新则version加1,否则提示更新0条 】
POST demo_users/_doc/123/_update
Request Body:
{
"doc": {
"userId": 1,
"username": "张三",
"role": "administrator",
"enabled": true,
"createdDate": "2020-01-01T12:00:00",
"remark": "仅演示POST更新5",
"updatedDate": "2020-01-17T15:30:00"
}
}
Response Body:
{
"_index": "demo_users",
"_type": "_doc",
"_id": "123",
"_version": 26,
"result": "updated",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 35,
"_primary_term": 1
}
Delete删除索引文档【DELETE index/type/id】
DELETE demo_users/_doc/123
Response Body:
{
"_index": "demo_users",
"_type": "_doc",
"_id": "123",
"_version": 2,
"result": "deleted",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 39,
"_primary_term": 1
}
Bulk批量操作文档【POST _bulk 或 index/_bulk 或 index/type/_bulk
一次请求支持进行多个索引、多个type的多种不同的CRUD操作,如果操作中有某个出现错误不会影响其它操作;】
POST _bulk
Request Body:(注意最后还得多一个换行,因为ES是根据换行符来识别多条命令的,如果缺少最后一条换行则会报错,注意请求体非标准的JSON,每行才是一个JSON,整体顶多可看成是 区分的JSON对象数组)
{ "index" : { "_index" : "demo_users_test", "_type" : "_doc", "_id" : "1" } }
{ "bulk_field1" : "测试创建index" }
{ "delete" : { "_index" : "demo_users", "_type" : "_doc", "_id" : "123" } }
{ "create" : { "_index" : "demo_users", "_type" : "_doc", "_id" : "2" } }
{ "bulk_field2" : "测试创建index2" }
{ "update" : { "_index" : "demo_users_test","_type" : "_doc","_id" : "1" } }
{ "doc": {"bulk_field1" : "测试创建index1","bulk_field2" : "测试创建index2"} }
Response Body:
{
"took": 162,
"errors": true,
"items": [
{
"index": {
"_index": "demo_users_test",
"_type": "_doc",
"_id": "1",
"_version": 8,
"result": "updated",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 7,
"_primary_term": 1,
"status": 200
}
},
{
"delete": {
"_index": "demo_users",
"_type": "_doc",
"_id": "123",
"_version": 2,
"result": "not_found",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 44,
"_primary_term": 1,
"status": 404
}
},
{
"create": {
"_index": "demo_users",
"_type": "_doc",
"_id": "2",
"status": 409,
"error": {
"type": "version_conflict_engine_exception",
"reason": "[_doc][2]: version conflict, document already exists (current version [1])",
"index_uuid": "u7WE286CQnGqhHeuwW7oyw",
"shard": "2",
"index": "demo_users"
}
}
},
{
"update": {
"_index": "demo_users_test",
"_type": "_doc",
"_id": "1",
"_version": 9,
"result": "updated",
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
},
"_seq_no": 8,
"_primary_term": 1,
"status": 200
}
}
]
}
mGet【POST _mget 或 index/_mget 或 index/type/_mget
,如果指定了index或type,则请求报文中则无需再指明index或type,可以通过_source指明要查询的include以及要排除exclude的字段】
POST _mget
Request Body:
{
"docs": [
{
"_index": "demo_users",
"_type": "_doc",
"_id": "12345"
},
{
"_index": "demo_users",
"_type": "_doc",
"_id": "1234567",
"_source": [
"userId",
"username",
"role"
]
},
{
"_index": "demo_users",
"_type": "_doc",
"_id": "1234",
"_source": {
"include": [
"userId",
"username"
],
"exclude": [
"role"
]
}
}
]
}
Response Body:
{
"docs":[
{
"_index":"demo_users",
"_type":"_doc",
"_id":"12345",
"_version":1,
"found":true,
"_source":{
"userId":1,
"username":"张三",
"role":"administrator",
"enabled":true,
"createdDate":"2020-01-01T12:00:00"
}
},
{
"_index":"demo_users",
"_type":"_doc",
"_id":"1234567",
"_version":7,
"found":true,
"_source":{
"role":"administrator",
"userId":1,
"username":"张三"
}
},
{
"_index":"demo_users",
"_type":"_doc",
"_id":"1234",
"_version":1,
"found":true,
"_source":{
"userId":1,
"username":"张三"
}
}
]
}
POST demo_users/_doc/_mget
Request Body:
{
"ids": [
"1234",
"12345",
"123457"
]
}
Response Body:
{
"docs":[
{
"_index":"demo_users",
"_type":"_doc",
"_id":"1234",
"_version":1,
"found":true,
"_source":{
"userId":1,
"username":"张三",
"role":"administrator",
"enabled":true,
"createdDate":"2020-01-01T12:00:00",
"remark":"仅演示"
}
},
{
"_index":"demo_users",
"_type":"_doc",
"_id":"12345",
"_version":1,
"found":true,
"_source":{
"userId":1,
"username":"张三",
"role":"administrator",
"enabled":true,
"createdDate":"2020-01-01T12:00:00"
}
},
{
"_index":"demo_users",
"_type":"_doc",
"_id":"123457",
"found":false
}
]
}
_update_by_query根据查询条件更新匹配到的索引文档的指定字段【POST index/_update_by_query
请求体写查询条件以及更新的字段,更新字段这里采用了painless脚本进行灵活更新】
POST demo_users/_update_by_query
Request Body:(意思是查询role=administrator【可能大家看到keyWord,这是因为role字段为text类型,无法直接匹配,需要借助于子字段role.keyword,如果有不理解后面会有简要说明】,更新role为poweruser、remark为remark+采用_update_by_query更新)
{
"script":{ "source":"ctx._source.role=params.role;ctx._source.remark=ctx._source.remark+params.remark",
"lang":"painless",
"params":{
"role":"poweruser",
"remark":"采用_update_by_query更新"
}
},
"query":{
"term":{
"role.keyword":"administrator"
}
}
}
painless写法请具体参考:painless语法教程
Response Body:
{
"took": 114,
"timed_out": false,
"total": 6,
"updated": 6,
"deleted": 0,
"batches": 1,
"version_conflicts": 0,
"noops": 0,
"retries": {
"bulk": 0,
"search": 0
},
"throttled_millis": 0,
"requests_per_second": -1,
"throttled_until_millis": 0,
"failures": [ ]
}
_delete_by_query根据查询条件删除匹配到的索引文档【 POST index/_delete_by_query
请求体写查询匹配条件】
POST demo_users/_delete_by_query
Request Body:(意思是查询enabled=false)
{
"query": {
"match": {
"enabled": false
}
}
}
Response Body:
{
"took":29,
"timed_out":false,
"total":3,
"deleted":3,
"batches":1,
"version_conflicts":0,
"noops":0,
"retries":{
"bulk":0,
"search":0
},
"throttled_millis":0,
"requests_per_second":-1,
"throttled_until_millis":0,
"failures":[
]
}
search查询
URL GET查询(GET index/_search?q=query_string语法,注意中文内容默认分词器是一个汉字拆分成一个term)
A.Term Query:【即分词片段(词条)查询,注意这里讲的包含是指与分词片段匹配】
GET /demo_users/_search?q=role:poweruser //指定字段查询,即:字段包含查询的值
GET /demo_users/_search?q=poweruser //泛查询(没有指定查询的字段),即查询文档中所有字段包含poweruser的值,只要有一个字段符合,那么该文档将会被返回
B.Phrase Query【即分组查询】
操作符有:AND / OR / NOT 或者表示为: && / || / !
+表示must -表示must_not 例如:field:(+a -b)意为field中必需包含a但不能包含b
GET /demo_users/_search?q=remark:(POST test)
GET /demo_users/_search?q=remark:(POST OR test)
GET /demo_users/_search?q=remark:"POST test"
//分组查询,即:查询remark中包含POST 或 test的文档记录
GET /demo_users/_search?q=remark:(test AND POST) //remark同时包含test与POST
GET /demo_users/_search?q=remark:(test NOT POST) //remark包含test但不包含POST
C.范围查询
区间表示:[]闭区间,{}开区间
如:year:[2019 TO 2020] 或 {2019 TO 2020} 或 {2019 TO 2020] 或 [* TO 2020]
算数符号
year:>2019 或 (>2012 && <=2020) 或 (+>=2012 +<=2020)
GET /demo_users/_search?q=userId:>123 //查询userId字段大于123的文档记录
D.通配符查询
?表示匹配任意1个字符,*表示匹配0或多个字符 例如:role:power* , role:use?
GET /demo_users/_search?q=role:power* //查询role字段前面是power,后面可以是0或多个其它任意字符。
可使用正则表达式,如:username:张三d+
可使用近似查询偏移量(slop)提高查询匹配结果【使用~N,N表示偏移量】
GET /demo_users/_search?q=remark:tett~1 //查询remark中包含test的文档,但实际写成了tett,故使用~1偏移近似查询,可以获得test的查询结果
GET /demo_users/_search?q=remark:"i like shenzhen"~2 //查询i like shenzhen但实际remark字段中值为:i like hubei and shenzhen,比查询值多了 hubei and,这里使用~2指定可偏移相隔2个term(这里即两个单词),最终也是可以查询出结果
DSL POST查询(POST index/_search)
POST demo_users/_search
Request Body:
{
"query":{
"bool":{
"must":[
{
"term":{
"enabled":"true" #查询enabled=true
}
},
{
"term":{
"role.keyword":"poweruser" #且role=poweruser
}
},
{
"query_string":{
"default_field":"username.keyword",
"query":"张三" #且 username 包含张三
}
}
],
"must_not":[
],
"should":[
]
}
},
"from":0,
"size":1000,
"sort":[
{
"createdDate":"desc" #根据createdDate倒序
}
],
"_source":{ #指明返回的字段,includes需返回字段,excludes不需要返回字段
"includes":[
"role",
"username",
"userId",
"remark"
],
"excludes":[
]
}
}
具体用法可参见:
【Elasticsearch】query_string的各种用法
Elasticsearch中 match、match_phrase、query_string和term的区别
Elasticsearch Query DSL 整理总结
[布尔查询Bool Query]
Indices APIs:负责索引Index的创建(create)、删除(delete)、获取(get)、索引存在(exist)等操作。
Document APIs:负责索引文档的创建(index)、删除(delete)、获取(get)等操作。
Search APIs:负责索引文档的search(查询),Document APIS根据doc_id进行查询,Search APIs]根据条件查询。
Aggregations:负责针对索引的文档各维度的聚合(Aggregation)。
cat APIs:负责查询索引相关的各类信息查询。
Cluster APIs:负责集群相关的各类信息查询。
--结束END--
本文标题: Elasticsearch必知必会的干货知识一:ES索引文档的CRUD
本文链接: https://lsjlt.com/news/3833.html(转载时请注明来源链接)
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