Elasticsearch: 权威指南---基础入门

1、查看
方式：GET
URL:http://10.10.6.225:9200/?pretty

pretty
在任意的查询字符串中增加pretty参数。会让Elasticsearch美化输出JSON结果以便更加容易阅读

实测：
http://10.10.6.225:9200/?pretty
与
http://10.10.6.225:9200/
效果是一样的。

返回：
{
"name": "Uf8MPqK",
"cluster_name": "elasticsearch",
"cluster_uuid": "w_SOItRIQBGpZ4UuMTRlDg",
"version": {
"number": "6.2.1",
"build_hash": "7299dc3",
"build_date": "2018-02-07T19:34:26.990113Z",
"build_snapshot": false,
"lucene_version": "7.2.1",
"minimum_wire_compatibility_version": "5.6.0",
"minimum_index_compatibility_version": "5.0.0"
},
"tagline": "You Know, for Search"
}
2、计算集群中文档的数量，我们可以用这个:
方式：POST
URL:http://10.10.6.225:9200/_count?pretty
BODY:
{
"query": {
"match_all": {}
}
}
返回：
{
"count": 1505295,
"_shards": {
"total": 36,
"successful": 36,
"skipped": 0,
"failed": 0
}
}
3、简单查询
URL:http://10.10.6.225:9200/megacorp/employee/_search?q=last_name:Smith
方式：GET
返回：
{
"took": 53,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 0.2876821,
"hits": [
{
"_index": "megacorp",
"_type": "employee",
"_id": "2",
"_score": 0.2876821,
"_source": {
"first_name": "Jane",
"last_name": "Smith",
"age": 32,
"about": "I like to collect rock albums",
"interests": [
"music"
]
}
},
{
"_index": "megacorp",
"_type": "employee",
"_id": "1",
"_score": 0.2876821,
"_source": {
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests": [
"sports",
"music"
]
}
}
]
}
}
也可以使用查询表达式：
URL:http://10.10.6.225:9200/megacorp/employee/_search
方式：POST
BODY:
{
"query" : {
"match" : {
"last_name" : "Smith"
}
}
}
4、复杂搜索
目标：同样搜索姓氏为 Smith 的雇员，但这次我们只需要年龄大于 30 的。查询需要稍作调整，使用过滤器 filter ，它支持高效地执行一个结构化查询。
URL:http://10.10.6.225:9200/megacorp/employee/_search
方式：POST
BODY:
{
"query" : {
"bool": {
"must": {
"match" : {
"last_name" : "smith"
}
},
"filter": {
"range" : {
"age" : { "gt" : 30 }
}
}
}
}
}

5、添加mapping
方式：PUT
URL: http://10.10.6.225:9200/megacorp/_mapping/employee/
{
"properties": {
"interests": {
"type": "text",
"fielddata": true
}
}
}
或者：
方式：POST
URL:http://10.10.6.225:9200/megacorp/employee/
{
"mappings": {
"_doc": {
"properties": {
"interests": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword"
}
}
}
}
}
}
}
7、聚合
URL:http://10.10.6.225:9200/megacorp/employee/_search
方式：POST
{
"size":0,
"aggs": {
"all_interests": {
"terms": { "field": "interests" }
}
}
}

叫Smith的聚合
URL:http://10.10.6.225:9200/megacorp/employee/_search
方式：POST

{"size":0,
"query": {
"match": {
"last_name": "smith"
}
},
"aggs": {
"all_interests": {
"terms": {
"field": "interests"
}
}
}
}
聚合还支持分级汇总 。比如，查询特定兴趣爱好员工的平均年龄：
URL:http://10.10.6.225:9200/megacorp/employee/_search
方式：POST
{
"size":0,
"aggs" : {
"all_interests" : {
"terms" : { "field" : "interests" },
"aggs" : {
"avg_age" : {
"avg" : { "field" : "age" }
}
}
}
}
}

遗留问题：

1、http://10.10.6.225:9200/megacorp/employee/_search  格式是megacorp+employee二层，而我们的是一层：http://10.10.6.225:9200/t_resource_info/_search，这肯定是有问题的，需要明天仔细讨论下。