我正在尝试在 Elasticsearch 上运行看似简单的查询,但我似乎无法获得我正在寻找的结果。
这是我正在尝试做的事情的一个简短示例:
我有一个新闻数据库。每条新闻都包含来源、标题、时间戳和用户。
我想要获取给定用户的每个可用来源的最后一个(基于时间戳的)标题。
#!/bin/bash
export ELASTICSEARCH_ENDPOINT="http://localhost:9200"
# Create indexes
curl -XPUT "$ELASTICSEARCH_ENDPOINT/news" -d '{
"mappings": {
"news": {
"properties": {
"source": { "type": "string", "index": "not_analyzed" },
"headline": { "type": "object" },
"timestamp": { "type": "date", "format": "date_hour_minute_second_millis" },
"user": { "type": "string", "index": "not_analyzed" }
}
}
}
}'
# Index documents
curl -XPOST "$ELASTICSEARCH_ENDPOINT/_bulk?refresh=true" -d '
{"index":{"_index":"news","_type":"news"}}
{"user": "John", "source": "CNN", "headline": "Great news", "timestamp": "2015-07-28T00:07:29.000"}
{"index":{"_index":"news","_type":"news"}}
{"user": "John", "source": "CNN", "headline": "More great news", "timestamp": "2015-07-28T00:08:23.000"}
{"index":{"_index":"news","_type":"news"}}
{"user": "John", "source": "ESPN", "headline": "Sports news", "timestamp": "2015-07-28T00:09:32.000"}
{"index":{"_index":"news","_type":"news"}}
{"user": "John", "source": "ESPN", "headline": "More sports news", "timestamp": "2015-07-28T00:10:35.000"}
{"index":{"_index":"news","_type":"news"}}
{"user": "Mary", "source": "Yahoo", "headline": "More news", "timestamp": "2015-07-28T00:11:54.000"}
{"index":{"_index":"news","_type":"news"}}
{"user": "Mary", "source": "Yahoo", "headline": "Crazy news", "timestamp": "2015-07-28T00:12:31.000"}
'
那么我如何获取 John 的最新 CNN 和 ESPN 头条新闻呢?
我一直在研究多重搜索 API,但这意味着我需要事先了解所有来源(在本例中为 CNN 和 ESPN)。