ES Script
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语言与es版本：
- Groovy：Es版本在1.4-5.0。
- Painless：是一种专门用于Elasticsearch的简单语言，用于内联和存储脚本，类似于java也有注释、关键词、类型、变量和函数等。安全的脚本语言，是ES的默认脚本语言，可以安全低用于内联和存储脚本。
- 其他脚本：
- expression：执行非常开的脚本语言，甚至比native脚本还快，支持javascript语法子集（单个表达式）。缺点是：只能访问数字、布尔、日期和geo_point字段，存储的字段不可用。
- mustache：提供模板参数化查询。
- java：java(专家API)
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painless语法
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基本语法：
"script": { "lang": "...", "source" | "id": "...", "params": { ... } } lang ：默认值painless。实际使用可以不设置，除非第二种语言供使用。
source：可以为inline脚本或者id，id对应一个stored脚本。
任何有名字的参数，可以被用于脚本的熟肉参数。
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expression脚本
GET product2/_search { "script_fields": { "test_field": { "script": { "lang": "expression", "source": "doc['price']" } } } }
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inline脚本
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创建简单文档
PUT twitter/_doc/1 { "user": "双榆树-张三", "message": "今儿天气不错啊，出去转转去", "uid": 2, "age": 20, "city": "北京", "province": "北京", "country": "中国", "address": "中国北京市海淀区", "location": { "lat": "39.970718", "lon": "116.325747" } } -
将 age 改为 30
POST /twitter/_update/1 { "script": { "lang": "painless" , "source": """ ctx._source.age=30 """ } } #运行结果 { "_index" : "twitter", "_type" : "_doc", "_id" : "1", "_version" : 2, "result" : "updated", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 1, "_primary_term" : 1 }
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概念："source": """ 表明是painless代码，这种代码写在DSL中，这种代码成为inline。
上下文：ctx成为上下文，用ctx._source访问对象的 _source 信息。
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脚本参数
脚本参数：inline中 script 中“ ctx._source.age=30 ”，这种实现方式会造成脚本每次执行都需要重新编译。编译好的script可以cache并共以后使用。
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script改进：
POST /twitter/_update/1 { "script": { "lang": "painless" , "source": """ ctx._source.age = params.value """ , "params": { "value":34 } } } # 增加params参数，并在脚本中通过params.参数名称进行引用
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存储脚本（stored script）
概念：script可以存储在一个集群cache中。可以通过ID进行调用，作用域为整个集群，只有发生变更时重新编译。
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参数设置：
- script.cache.expire：设置存储脚本的过期时间，默认没有过期时间。
- script.cache.max_size：设置缓存大小，默认100MB。
- script.max_size_in_bytes：设置脚本大小，默认最大64MB。
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代码示例：
# 定义一个Id为add_age的存储脚本 POST /_scripts/add_age { "script":{ "lang" : "painless" , "source": """ ctx._source.age = params.age """ } } ## 引用存储脚本 POST /twitter/_update/1 { "script": { "id": "add_age" , "params": { "age":45 } } }
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访问source里的字段
- 概述：Painless中用于访问上下文中的语法取决于上下文。 在ES中，有许多不同的Painless上下文。
- Painless上下文：包括ingest processor，update， update by query，sort，filter等。
- Content访问字段：Ingest node 访问字段用 ctx.field_name; updates 访问字段用ctx._source.field_name。
- updates：包含update、reindex和update by query。
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Painless脚本样例-1（ctx.field_name）
# 利用pipeline 创建一个字段 PUT _ingest/pipeline/add_field_c { "processors": [ {"script": { "lang": "painless" , "source": """ ctx.field_c = (ctx.field_a + ctx.field_b) * params.value """ , "params": { "value":2 } }} ] } # 创建文档 PUT test_script/_doc/1?pipeline=add_field_c { "field_a":10, "field_b":24 } # 创建文档执行结果 { "_index" : "test_script", "_type" : "_doc", "_id" : "1", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 1 } #查询创建文档结果, 新增字段 field_c GET test_script/_search { "took" : 0, "timed_out" : false, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 1, "relation" : "eq" }, "max_score" : 1.0, "hits" : [ { "_index" : "test_script", "_type" : "_doc", "_id" : "1", "_score" : 1.0, "_source" : { "field_c" : 68, "field_a" : 10, "field_b" : 24 } } ] } }
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Painless脚本样例-2（ctx.field_name）
#利用pipeline，检查category，如果为空，则置为None # 创建pipeline PUT _ingest/pipeline/blogs_pipeline { "processors": [ {"script": { "lang": "painless" , "source": """ if(ctx.category == ""){ ctx.category = "None" } """ }} ] } # 利用pipeline，检查修改category PUT test_script/_doc/2?pipeline=blogs_pipeline { "field_a":5, "field_b":10, "category":"" } # 执行结果 { "_index" : "test_script", "_type" : "_doc", "_id" : "2", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 1, "_primary_term" : 1 } #查询文档信息 将category字段修改为“None” GET test_script/_doc/2 { "_index" : "test_script", "_type" : "_doc", "_id" : "2", "_version" : 1, "_seq_no" : 1, "_primary_term" : 1, "found" : true, "_source" : { "field_a" : 5, "field_b" : 10, "category" : "None" } }
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Painless脚本样例-3（ctx._source.field_name）
#增加数据 PUT test_source/_doc/1 { "counter": 1, "tags": ["red"] } # 给id为1的doc增加颜色green POST /test_source/_update/1 { "script": { "lang": "painless" , "source": """ ctx._source.tags.add(params.color); """ , "params": { "color":"green" } } } #查询doc GET test_source/_doc/1 { "_index" : "test_source", "_type" : "_doc", "_id" : "1", "_version" : 2, "_seq_no" : 1, "_primary_term" : 1, "found" : true, "_source" : { "counter" : 1, "tags" : [ "red", "green" ] } }
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Painless脚本样例-4（ctx._source.field_name）
# 列表中删除元素 POST /test_source/_update/1 { "script": { "lang": "painless" , "source": """ if(ctx._source.tags.contains(params.color)){ ctx._source.tags.remove(ctx._source.tags.indexOf(params.color)) } """ , "params": { "color":"red" } } }
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Painless脚本获取文档值：doc['field'].value和params['_source']['field']
doc['field']【推荐】：导致该西段的条件被加载到内存（缓存），从而保证执行更快，但消耗更多的内存。另外，doc['field']只能获取简单类型，不能获取复杂类型（如object 和 nested类型）。
params['_source']['field']：每次使用时都必须加载并解析，性能比较低。
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Painless脚本简单操练初始化数据
PUT hockey/_bulk?refresh {"index":{"_id":1}} {"first":"johnny","last":"gaudreau","goals":[9,27,1],"assists":[17,46,0],"gp":[26,82,1],"born":"1993/08/13"} {"index":{"_id":2}} {"first":"sean","last":"monohan","goals":[7,54,26],"assists":[11,26,13],"gp":[26,82,82],"born":"1994/10/12"} {"index":{"_id":3}} {"first":"jiri","last":"hudler","goals":[5,34,36],"assists":[11,62,42],"gp":[24,80,79],"born":"1984/01/04"} {"index":{"_id":4}} {"first":"micheal","last":"frolik","goals":[4,6,15],"assists":[8,23,15],"gp":[26,82,82],"born":"1988/02/17"} {"index":{"_id":5}} {"first":"sam","last":"bennett","goals":[5,0,0],"assists":[8,1,0],"gp":[26,1,0],"born":"1996/06/20"} {"index":{"_id":6}} {"first":"dennis","last":"wideman","goals":[0,26,15],"assists":[11,30,24],"gp":[26,81,82],"born":"1983/03/20"} {"index":{"_id":7}} {"first":"david","last":"jones","goals":[7,19,5],"assists":[3,17,4],"gp":[26,45,34],"born":"1984/08/10"} {"index":{"_id":8}} {"first":"tj","last":"brodie","goals":[2,14,7],"assists":[8,42,30],"gp":[26,82,82],"born":"1990/06/07"} {"index":{"_id":39}} {"first":"mark","last":"giordano","goals":[6,30,15],"assists":[3,30,24],"gp":[26,60,63],"born":"1983/10/03"} {"index":{"_id":10}} {"first":"mikael","last":"backlund","goals":[3,15,13],"assists":[6,24,18],"gp":[26,82,82],"born":"1989/03/17"} {"index":{"_id":11}} {"first":"joe","last":"colborne","goals":[3,18,13],"assists":[6,20,24],"gp":[26,67,82],"born":"1990/01/30"}
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Painless脚本简单操练--计算玩家的总进球数
GET hockey/_search { "script_fields": { "total_goals": { "script": { "lang": "painless" , "source": """ int total = 0; for(int i=0; i< doc['goals'].length; i++){ total += doc['goals'][i]; } return total; """ } } } }
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Painless脚本简单操练--添加nickname为hockey新字段
POST hockey/_update/1 { "script": { "lang": "painless", "source": """ ctx._source.last = params.last; ctx._source.nick = params.nick """, "params": { "last": "gaudreau", "nick": "hockey" } } } -
Painless脚本简单操练--操作日期类型
GET hockey/_search { "script_fields": { "birth_year": { "script": { "source": "doc.born.value.year" } } ,"birth_month": { "script": { "source": "doc.born.value.month" } } } }
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Painless脚本简单操练--统计男性嫌疑人的数量
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初始化信息
PUT test_index/_bulk?refresh {"index":{"_id":1}} {"ajbh": "12345","ajmc": "立案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三","NL": "30","SF": "男"},{"XM": "李四","NL": "31","SF": "男"},{"XM": "王五","NL": "30","SF": "女"},{"XM": "赵六","NL": "23","SF": "男"}]} {"index":{"_id":2}} {"ajbh": "563245","ajmc": "结案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三2","NL": "30","SF": "男"},{"XM": "李四2","NL": "31","SF": "男"},{"XM": "王五2","NL": "30","SF": "女"},{"XM": "赵六2","NL": "23","SF": "女"}]} {"index":{"_id":3}} {"ajbh": "12345","ajmc": "立案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三3","NL": "30","SF": "男"},{"XM": "李四3","NL": "31","SF": "男"},{"XM": "王五3","NL": "30","SF": "女"},{"XM": "赵六3","NL": "23","SF": "男"}]} -
统计男性嫌疑人的数量
GET test_index/_search { "script_fields": { "total": { "script": { "lang": "painless" , "source": """ int total = 0; for(int i=0; i< params['_source']['jsbax_sjjh2_xz_ryjbxx_cleaning'].length; i++){ if(params['_source']['jsbax_sjjh2_xz_ryjbxx_cleaning'][i]['SF'] == '男'){ total++; } } return total; """ } } } , "aggs": { "total": { "sum": { "script": { "lang": "painless" , "source": """ int total = 0; for(int i=0; i< params['_source']['jsbax_sjjh2_xz_ryjbxx_cleaning'].length; i++){ if(params['_source']['jsbax_sjjh2_xz_ryjbxx_cleaning'][i]['SF'] == '男'){ total++; } } return total; """ } } } } } #执行结果 { "took" : 6, "timed_out" : false, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 3, "relation" : "eq" }, "max_score" : 1.0, "hits" : [ { "_index" : "test_index", "_type" : "_doc", "_id" : "1", "_score" : 1.0, "fields" : { "total" : [ 3 ] } }, { "_index" : "test_index", "_type" : "_doc", "_id" : "2", "_score" : 1.0, "fields" : { "total" : [ 2 ] } }, { "_index" : "test_index", "_type" : "_doc", "_id" : "3", "_score" : 1.0, "fields" : { "total" : [ 3 ] } } ] }, "aggregations" : { "total" : { "value" : 8.0 } } }
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*
POST /product2/_update/4
{
"script": {
"source": "ctx._source.price -=1"
}
}
POST /product2/_update/4
{
"script": "ctx._source.price -=1"
}
DELETE test_index;
PUT test_index/_bulk?refresh
{"index":{"_id":1}}
{"ajbh": "12345","ajmc": "立案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三","NL": "30","SF": "男"},{"XM": "李四","NL": "31","SF": "男"},{"XM": "王五","NL": "30","SF": "女"},{"XM": "赵六","NL": "23","SF": "男"}]}
{"index":{"_id":2}}
{"ajbh": "563245","ajmc": "结案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三2","NL": "30","SF": "男"},{"XM": "李四2","NL": "31","SF": "男"},{"XM": "王五2","NL": "30","SF": "女"},{"XM": "赵六2","NL": "23","SF": "女"}]}
{"index":{"_id":3}}
{"ajbh": "12345","ajmc": "立案案件","lasj": "2020/05/21 13:25:23","jsbax_sjjh2_xz_ryjbxx_cleaning": [{"XM": "张三3","NL": "30","SF": "男"},{"XM": "李四3","NL": "31","SF": "男"},{"XM": "王五3","NL": "30","SF": "女"},{"XM": "赵六3","NL": "23","SF": "男"}]}
