Elasticsearch 7.X DSL 入门教程

基础概念

什么是 DSL

DSL (Domain Specific Language) 是 Elasticsearch 的查询语言，基于 JSON 格式，用于执行各种数据操作。

核心概念

{ "index": "索引名", // 类似数据库 "type": "类型名", // 7.x 已废弃，统一为 _doc "id": "文档ID", // 类似主键 "document": "文档内容" // 类似记录 }

索引操作

创建索引

PUT /products { "settings": { "number_of_shards": 3, "number_of_replicas": 1 }, "mappings": { "properties": { "name": { "type": "text", "analyzer": "ik_max_word" }, "price": { "type": "double" }, "category": { "type": "keyword" }, "description": { "type": "text", "analyzer": "ik_max_word" }, "stock": { "type": "integer" }, "created_at": { "type": "date", "format": "yyyy-MM-dd HH:mm:ss" }, "is_active": { "type": "boolean" } } } }

查看索引

GET /products GET /products/_mapping GET /_cat/indices?v

删除索引

DELETE /products

文档操作

创建文档

POST /products/_doc { "name": "iPhone 15 Pro", "price": 7999, "category": "手机", "description": "苹果最新款智能手机", "stock": 100, "created_at": "2024-01-15 10:00:00", "is_active": true }

创建指定 ID 文档

PUT /products/_doc/1 { "name": "MacBook Pro", "price": 12999, "category": "电脑", "description": "苹果专业笔记本电脑", "stock": 50, "created_at": "2024-01-15 11:00:00", "is_active": true }

批量创建文档

POST /_bulk { "index": { "_index": "products", "_id": "2" } } { "name": "iPad Air", "price": 4399, "category": "平板", "description": "轻薄平板电脑", "stock": 80, "created_at": "2024-01-15 12:00:00", "is_active": true } { "index": { "_index": "products", "_id": "3" } } { "name": "AirPods Pro", "price": 1899, "category": "耳机", "description": "无线降噪耳机", "stock": 200, "created_at": "2024-01-15 13:00:00", "is_active": true } { "index": { "_index": "products", "_id": "4" } } { "name": "Apple Watch", "price": 2999, "category": "手表", "description": "智能手表", "stock": 150, "created_at": "2024-01-15 14:00:00", "is_active": true }

查询文档

GET /products/_doc/1

更新文档

POST /products/_update/1 { "doc": { "price": 11999, "stock": 45 } }

删除文档

DELETE /products/_doc/1

基础查询

查询所有文档

GET /products/_search { "query": { "match_all": {} } }

分页查询

GET /products/_search { "query": { "match_all": {} }, "from": 0, "size": 10 }

指定返回字段

GET /products/_search { "query": { "match_all": {} }, "_source": ["name", "price", "category"] }

排序

GET /products/_search { "query": { "match_all": {} }, "sort": [ { "price": { "order": "desc" } } ] }

查询类型详解

1. Match Query（全文搜索）

GET /products/_search { "query": { "match": { "name": "苹果 手机" } } }

2. Term Query（精确匹配）

GET /products/_search { "query": { "term": { "category": "手机" } } }

3. Terms Query（多值精确匹配）

GET /products/_search { "query": { "terms": { "category": ["手机", "电脑"] } } }

4. Range Query（范围查询）

GET /products/_search { "query": { "range": { "price": { "gte": 1000, "lte": 10000 } } } }

范围操作符：

• gt: 大于
• gte: 大于等于
• lt: 小于
• lte: 小于等于

5. Prefix Query（前缀匹配）

GET /products/_search { "query": { "prefix": { "name": "iPh" } } }

6. Wildcard Query（通配符匹配）

GET /products/_search { "query": { "wildcard": { "name": "*Pro*" } } }

7. Fuzzy Query（模糊查询）

GET /products/_search { "query": { "fuzzy": { "name": { "value": "iPone", "fuzziness": 2 } } } }

8. Bool Query（布尔查询）

GET /products/_search { "query": { "bool": { "must": [ { "match": { "name": "苹果" } } ], "must_not": [ { "term": { "category": "耳机" } } ], "should": [ { "range": { "price": { "lte": 5000 } } } ], "filter": [ { "term": { "is_active": true } } ] } } }

Bool 子句说明：

• must: 必须匹配（影响得分）
• must_not: 必须不匹配
• should: 应该匹配（影响得分）
• filter: 必须匹配（不影响得分）

复合查询

1. Multi Match Query（多字段搜索）

GET /products/_search { "query": { "multi_match": { "query": "苹果", "fields": ["name", "description"] } } }

2. Query String Query（查询字符串）

GET /products/_search { "query": { "query_string": { "fields": ["name", "description"], "query": "(苹果 AND 手机) OR (iPad)" } } }

3. Nested Bool Query（嵌套布尔查询）

GET /products/_search { "query": { "bool": { "must": [ { "bool": { "should": [ { "match": { "name": "苹果" } }, { "match": { "description": "苹果" } } ] } }, { "range": { "price": { "gte": 1000 } } } ] } } }

聚合查询

1. Terms Aggregation（词项聚合）

GET /products/_search { "size": 0, "aggs": { "category_count": { "terms": { "field": "category", "size": 10 } } } }

2. Stats Aggregation（统计聚合）

GET /products/_search { "size": 0, "aggs": { "price_stats": { "stats": { "field": "price" } } } }

返回：count、min、max、avg、sum

3. Range Aggregation（范围聚合）

GET /products/_search { "size": 0, "aggs": { "price_ranges": { "range": { "field": "price", "ranges": [ { "to": 2000 }, { "from": 2000, "to": 5000 }, { "from": 5000 } ] } } } }

4. Date Histogram Aggregation（日期直方图）

GET /products/_search { "size": 0, "aggs": { "products_over_time": { "date_histogram": { "field": "created_at", "calendar_interval": "day", "format": "yyyy-MM-dd" } } } }

5. Bucket Aggregation + Metric Aggregation（桶聚合 + 指标聚合）

GET /products/_search { "size": 0, "aggs": { "by_category": { "terms": { "field": "category" }, "aggs": { "average_price": { "avg": { "field": "price" } }, "max_price": { "max": { "field": "price" } } } } } }

6. Filter Aggregation（过滤聚合）

GET /products/_search { "size": 0, "aggs": { "active_products": { "filter": { "term": { "is_active": true } }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } } }

高级功能

1. Highlight（高亮显示）

GET /products/_search { "query": { "match": { "name": "苹果" } }, "highlight": { "fields": { "name": {}, "description": {} } } }

2. Script Fields（脚本字段）

GET /products/_search { "query": { "match_all": {} }, "script_fields": { "discount_price": { "script": { "source": "doc['price'].value * 0.9" } } } }

3. Source Filtering（源过滤）

GET /products/_search { "query": { "match_all": {} }, "_source": { "includes": ["name", "price"], "excludes": ["description"] } }

4. Explain（解释查询）

GET /products/_search { "query": { "match": { "name": "苹果" } }, "explain": true }

5. Profile（性能分析）

GET /products/_search { "profile": true, "query": { "match": { "name": "苹果" } } }

实战示例

示例 1: 电商商品搜索

GET /products/_search { "query": { "bool": { "must": [ { "multi_match": { "query": "苹果", "fields": ["name^2", "description"], "type": "best_fields" } } ], "filter": [ { "term": { "is_active": true } }, { "range": { "price": { "gte": 1000, "lte": 15000 } } } ] } }, "aggs": { "categories": { "terms": { "field": "category", "size": 10 } }, "price_ranges": { "range": { "field": "price", "ranges": [ { "to": 2000, "key": "低价" }, { "from": 2000, "to": 5000, "key": "中价" }, { "from": 5000, "key": "高价" } ] } } }, "sort": [ { "_score": { "order": "desc" } } ], "from": 0, "size": 20, "highlight": { "fields": { "name": {}, "description": {} }, "pre_tags": ["<em>"], "post_tags": ["</em>"] } }

示例 2: 日志分析

GET /logs/_search { "query": { "bool": { "must": [ { "range": { "@timestamp": { "gte": "now-24h", "lte": "now" } } } ], "filter": [ { "term": { "level": "ERROR" } } ] } }, "aggs": { "errors_by_service": { "terms": { "field": "service_name", "size": 20 }, "aggs": { "error_types": { "terms": { "field": "error_type", "size": 10 } }, "timeline": { "date_histogram": { "field": "@timestamp", "calendar_interval": "1h" } } } } }, "sort": [ { "@timestamp": { "order": "desc" } } ], "size": 100 }

示例 3: 用户行为分析

GET /user_actions/_search { "query": { "bool": { "must": [ { "range": { "timestamp": { "gte": "now-7d/d", "lte": "now/d" } } } ] } }, "aggs": { "daily_stats": { "date_histogram": { "field": "timestamp", "calendar_interval": "day" }, "aggs": { "unique_users": { "cardinality": { "field": "user_id" } }, "action_types": { "terms": { "field": "action_type" } } } }, "top_users": { "terms": { "field": "user_id", "size": 10, "order": { "action_count": "desc" } }, "aggs": { "action_count": { "value_count": { "field": "_id" } } } } } }

示例 4: 复杂的多条件查询

GET /products/_search { "query": { "bool": { "must": [ { "bool": { "should": [ { "match": { "name": "手机" } }, { "match": { "description": "手机" } } ], "minimum_should_match": 1 } } ], "must_not": [ { "term": { "category": "配件" } } ], "should": [ { "range": { "price": { "lte": 3000 } } }, { "term": { "stock": { "value": 0 } } } ], "filter": [ { "term": { "is_active": true } }, { "range": { "created_at": { "gte": "now-30d" } } } ] } }, "aggs": { "category_stats": { "terms": { "field": "category" }, "aggs": { "price_stats": { "stats": { "field": "price" } }, "stock_stats": { "stats": { "field": "stock" } } } } }, "sort": [ { "price": { "order": "asc" } }, { "_score": { "order": "desc" } } ], "from": 0, "size": 20 }

常用操作符和参数

查询参数

排序参数

聚合参数

性能优化建议

1. 使用 filter 而非 query

// 不推荐 GET /products/_search { "query": { "term": { "is_active": true } } } // 推荐 GET /products/_search { "query": { "bool": { "filter": [ { "term": { "is_active": true } } ] } } }

2. 限制返回字段

GET /products/_search { "_source": ["name", "price"], "query": { "match_all": {} } }

3. 使用 scroll 处理大量数据

GET /products/_search { "scroll": "1m", "size": 1000, "query": { "match_all": {} } }

4. 避免深度分页

// 使用 search_after 代替 from/size GET /products/_search { "size": 100, "query": { "match_all": {} }, "sort": [ { "_id": "asc" } ], "search_after": ["last_document_id"] }

总结

Elasticsearch DSL 的核心要点：

1. 查询类型：match、term、range、bool 等
2. 复合查询：bool 查询的 must、must_not、should、filter
3. 聚合分析：terms、stats、range、date_histogram 等
4. 高级功能：highlight、script、explain、profile
5. 性能优化：使用 filter、限制字段、避免深度分页

通过本教程，你应该能够：

• 创建和管理索引
• 执行各种类型的查询
• 进行数据聚合分析
• 优化查询性能

继续实践和探索，你会发现 Elasticsearch DSL 的强大之处！