一、简介
在Elasticsearch中，我们可以使用Elasticsearch-DSL（Elasticsearch Domain Specific Language）来构建和执行复杂的搜索查询。官方Query DSL指导文档。
叶查询：在特定字段中寻找特定值,例如 match ,term 或 range。
复合查询：具有查询子句或逻辑方式组和查询如 bool dis_max 包含must should must_not子句。
#全量查询
#匹配查询
#范围查询
#多字段查询
#过滤查询
#高亮查询
#分页查询
#排序查询
#聚合查询 如计算价格的平均值 最大 最小
#复合查询 bool查询 可以包含must should must_not子句二、DSL查询用法举例
0、准备测试数据
创建索引添加映射关系
PUT http://192.168.77.176:9200/vegetables
#body内容 josn格式
{
"mappings": {
"properties": {
"name": {
"type": "text",
"analyzer": "ik_smart"
},
"price": {
"type": "float"
},
"weight": {
"type": "float"
},
"origin": {
"type": "text",
"analyzer": "ik_smart"
},
"purchase_date": {
"type": "date"
},
"description": {
"type": "text",
"analyzer": "ik_smart"
}
}
}
}
批量写入数据
POST http://192.168.77.176:9200/vegetables/_bulk
#body内容 josn格式
{"index": {}}
{"name": "西红柿", "price": 3.5, "weight": 0.2, "origin": "山东", "purchase_date": "2023-01-01", "description": "新鲜西红柿，口感酸甜。"}
{"index": {}}
{"name": "黄瓜", "price": 2.0, "weight": 0.3, "origin": "河北", "purchase_date": "2023-01-02", "description": "新鲜黄瓜，脆嫩多汁。"}
{"index": {}}
{"name": "茄子", "price": 4.0, "weight": 0.4, "origin": "河南", "purchase_date": "2023-01-03", "description": "新鲜茄子，肉质细腻。"}
{"index": {}}
{"name": "土豆", "price": 1.5, "weight": 0.5, "origin": "内蒙古", "purchase_date": "2023-01-04", "description": "新鲜土豆，口感粉糯。"}
{"index": {}}
{"name": "胡萝卜", "price": 2.5, "weight": 0.25, "origin": "山西", "purchase_date": "2023-01-05", "description": "新鲜胡萝卜，色泽鲜艳。"}
1.匹配查询 match
#全量匹配查询
GET http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"match_all": {}
}
}
#单个匹配查询
GET http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query":{
"match":{
"name": "黄瓜"
}
}
}
2.精确匹配查询 term 官方指导文档
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"term": {
"price": 4.0
}
}
}
3.范围查询 range
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"range": {
"price": {
"gte": 3,
"lte": 4
}
}
}
}
4.多字段匹配查询 multi_match
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"multi_match": {
"query": "黄瓜",
"fields": ["name", "description"]
}
}
}
5.过滤查询 filter
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"bool": {
"must": [
{
"multi_match": {
"query": "黄瓜",
"fields": ["name", "description"]
}
}
],
"filter": [
{
"term": {
"price": 2.0
}
}
]
}
}
}
6.高亮查询 返回高亮结果
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"size": 0,
"aggs": {
"your_aggregation": {
"terms": {
"field": "your_field",
"size": 10
}
}
}
}7.分页查询
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式 每页显示2条数据，从序号0开始，即查询第1页
{
"from": 0,
"size": 2,
"query": {
"match_all": {}
}
}
#body内容 josn格式 每页显示3条数据，从序号9开始（前3页需要0-8），即查询第4页
{
"from": 9,
"size": 3,
"query": {
"match_all": {}
}
}第一页数据是西红柿 黄瓜
8.排序查询
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"match_all": {}
},
"sort": [
{ "price": "asc" }
]
}ase升序 desc降序 西红柿最便宜排在最前面
9.聚合查询
POST http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"size": 0,
"aggs": {
"your_aggregation": {
"terms": {
"field": "your_field",
"size": 10
}
}
}
}10.复合查询 bool查询 包含must should must_not子句
复合查询例子，它要求：
文章的标题中必须包含"Elasticsearch"这个词。
文章的内容中必须包含"distributed search"这个词。
文章的发布日期必须在2024年内。
至少有一个特征，例如文章被标记为featured_article。
文章不能被标记为retired。POSR http://192.168.77.176:9200/vegetables/_search
#body内容 josn格式
{
"query": {
"bool": {
"must": [
{
"match": {
"title": "Elasticsearch"
}
},
{
"match": {
"content": "distributed search"
}
}
],
"filter": [
{
"range": {
"date": {
"gte": "2024-01-01",
"lte": "2024-12-31"
}
}
}
],
"should": [
{
"match": {
"featured_article": true
}
}
],
"must_not": [
{
"match": {
"retired": true
}
}
]
}
}
}