场景: 

   XX对象的告警个数字段是数字, 优先级字段是数字

  排序要求: 优先告警个数大->小, 其次优先级大->小

问题: 

告警个数字段不存在或者值为0的情况是等价的,排序上应该是平等的.

不应该存在0的大于字段不存在的

处理: 

    对没有告警个数字段的默认设置0 , 那么排序的时候才正确

    使用Missing - 给字段设置默认值

一般用于排序时，该字段没有值，使用missing赋值默认值，然后就用赋的值进行排序

GET indexname/_search
{"sort": [{"alarmNum": {"order": "asc","missing": 0    -- 此字段不存在的时候, 值为0 . 与值0是一样排序 }},{"priority_code":{"order": "asc"}}],"from":0,"size":100
}

unmapped_type - 容错不存在的字段

如果mapping中无此字段，则搜索请求将失败.unmapped_type选项允许您忽略没有mapping的字段，也不按它们排序。参数的值为该字段对应值的类型。

这种场景一般不存在.因为index至少有一条数据存在此字段有值,mapper里面就有

如何不报错?

GET project_base_info/_search
{"sort": [{"alarmNum1": {"order": "asc","missing": 0,"unmapped_type":"long"  -- 有了此配置 ,mapper没有也不会报错}},{"project_priority_code":{"order": "asc"}}],"from":0,"size":100
}

pipeline 设置默认值:属于前置设置默认值

在插入数据时候,给字段设置给默认值. 但问题是,后续也无法修改此字段. 这个应该很少有这个需求

PUT _ingest/pipeline/add_zcy_pipeline
{"processors": [{"set": {"field": "projectCode","value": "10000000"}}]
}设置projectCode 默认值10000000创建索引:
PUT projecy_zcy3
{"settings": {"refresh_interval": "1s","number_of_shards": 1,"number_of_replicas": 1,"index":{"default_pipeline":"add_zcy_pipeline"}},"mappings": {"properties": {"id": {"type": "text","fields": {"keyword": {"type": "keyword"},"keylong": {"type": "long"}}},"projectCode": {"type": "text"},"projectName": {"type": "text","fields": {"keyword": {"type": "keyword"}}},"projectStatus": {"type": "keyword"}}}
}插入数据
PUT projecy_zcy3/_doc/2
{"id":"1022","projectName":"ssss"
}
结果:"_source" : {"projectCode" : "10000000","id" : "1022","projectName" : "ssss"}
PUT projecy_zcy3/_doc/2
{"id":"1022","projectName":"ssss","projectCode":"111"
}
结果还是"_source" : {"projectCode" : "10000000","id" : "1022","projectName" : "ssss"}

设置默认值--script执行批量

# 批量更新脚本
POST customer/_update_by_query
{"script": {"lang": "painless","source": "if (ctx._source.major == null) {ctx._source.major = 'student'}"}
}

设置默认值--借助 pipeline script 更新

PUT _ingest/pipeline/update_pipeline
{"processors": [{"script": {"lang": "painless","source": """if (ctx['major'] == null) {ctx['major'] = 'student'}"""}}]
}
POST customer/_doc/4
{"major":null
}
POST customer/_update_by_query?pipeline=update_pipeline
{"query": {"match_all": {}}
}