elasticsearch7 基本语法
注意：
megacorp：是index
employee：是type
使用es版本是7.1.1
在postman下进行的模拟
下面的方面省略了host，完整的是类似 http://127.0.0.1:9200/website/blog/123
参考：elasticsearch权威指南
通过id进行查询
GET megacorp/employee/1?_source=last_name,age
_id=1 且只显示last_name,age字段
全文搜索
既能匹配出完整完整的rock climbing,又能匹配出带有rock 或climbing 词的
GET /megacorp/employee/_search
{
"query" : {
"match" : {
"about" : "rock climbing"
}
}
}
短语搜索
想要确切的匹配若干个单词或者短语(phrases),match_phrase查询即可
GET /megacorp/employee/_search
{
"query" : {
"match_phrase" : {
"about" : "rock climbing"
}
}
}
多条件搜索
filter是区间过滤器(range filter),下面匹配的是:姓氏为“Smith”的员工，且年龄大于30岁的员工
GET megacorp/employee/_search
{
"query" : {
"bool" : {
"filter" : {
"range" : {
"age" : { "gt" : 30 }
}
},
"must" : {
"match" : {
"last_name" : "smith"
}
}
}
}
}
聚合搜索
类似于group by,下面会把interests的进行group by,获得不同兴趣的数量
GET megacorp/employee/_search
{
"aggs": {
"all_interests": {
"terms": { "field": "interests.keyword" }
}
}
}
获得不同兴趣的平均年龄(进行两次分级汇总)
GET megacorp/employee/_search
{
"aggs": {
"all_interests": {
"terms": {
"field": "interests.keyword"
},
"aggs":{
"avg_age":{
"avg":{
"field":"age"
}
}
}
}
}
}
新增数据
如果_id=123已经存在，则会覆盖老的，注意这里的覆盖是新的完全替代了老的值，不会仅仅替代新老共同的字段，
返回值result的val也会不一样
PUT megacorp/employee/123
{
"first_name" : "z",
"last_name" : "yk",
"age" : 18,
"about": "I like to study",
"interests": [ "music" ]
}
返回值：
{
"_index": "megacorp",
"_type": "employee",
"_id": "123",
"_version": 1,//操作的次数，每操作一次这个数据就+1
"result": "created",//因为是之前没有的数据所以是created，如果再请求一次会变成updated
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 3,
"_primary_term": 1
}
防重复新增数据
PUT website/blog/1/_create
{
"title": "My first blog entry",
"text": "Just trying this out..."
}
局部更新
相同字段会覆盖，没有的字段会新增
POST website/blog/1/_update
// doc是固定语法，doc的值是要更新的内容
{
"doc" : {
"tags" : [ "testing" ],
"views": 0
}
}
查询结果
website/blog/1
{
"_index": "website",
"_type": "blog",
"_id": "1",
"_version": 6,
"_seq_no": 7,
"_primary_term": 1,
"found": true,
"_source": {
"title": "My first external blog entry",
"text": "Starting to get the hang of this...",
//新增的值
"views": 0,
"tags": [
"testing"
]
}
}
使用脚本更新
对某个字段值进行数学运算
POST website/blog/1/_update
{
"script" : "ctx._source.views+=1" //views+1
}
查询返回结果views这个字段会比之前多1
往数组里加字符串
POST website/blog/2/_update
{
"script":{
"source" : "ctx._source.tags.add (params.new_tag)", // params.new_tag是取参数值的意思
"params" : {
"new_tag" : "search"
}
}
}
查询更新之后的结果(部分)
{
"_source": {
"title": "My first external blog entry",
"text": "Starting to get the hang of this...",
"views": 1,
"tags": [
"testing",
"search" //这个是新添加的值
]
}
}
添加到字符串
POST website/blog/2/_update
{
"script":{
"source" : "ctx._source.title += (params.new_tag)",
"params" : {
"new_tag" : "search"
}
}
}
返回结果
{
"_source": {
"title": "My first external blog entrysearch", // 这个search是新添加的
"text": "Starting to get the hang of this...",
"views": 1,
}
}
根据条件更新
POST website/blog/2/_update
{
"script":{
"source" : "ctx.op = ctx._source.views == params.count ? 'delete':'none'", //如果views=count的值则删除
"params" : {
"count" : 0
}
}
}
成功的时候返回successful的数量>=1
{
"_index": "website",
"_type": "blog",
"_id": "2",
"_version": 4,
"result": "deleted",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 12,
"_primary_term": 1
}
更新可能不存在的数据
POST website/blog/2/_update
{
"script" : "ctx._source.views+=1",
"upsert": {
"views": 1 //不存在的时候的初始值
}
}
批量搜索
一次查询多条数据
POST /_mget
{
"docs" : [
{
"_index" : "website",// 要搜索的index
"_type" : "blog", //要搜索的type
"_id" : 2 //要搜索的id
},
{
"_index" : "website",
"_type" : "blog",
"_id" : 1,
"_source": "views" // 具体要展示的数据
}
]
}
在url里指定index和type，多个id可以用ids
POST website/blog/_mget
{
"ids" : [ "2", "1" ]
}