ElasticSearch 找不到字符串字段中存在的确切值答案

【问题标题】：ElasticSearch cannot find an exact value that exists in a string fieldElasticSearch 找不到字符串字段中存在的确切值
【发布时间】：2017-04-15 12:07:55
【问题描述】：

当我执行空查询以列出一些结果时，我看到值在那里。例如：

{
    "took": 6,
    "timed_out": false,
    "_shards": {
        "total": 5,
        "successful": 5,
        "failed": 0
    },
    "hits": {
        "total": 3024,
        "max_score": 1.0,
        "hits": [{
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5-j6uVuoyTMhX204",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1029.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5-mTuVuoyTMhX205",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1321.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5-xkuVuoyTMhX209",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail2567.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5zr8uVuoyTMhX20F",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail2122.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5z23uVuoyTMhX20L",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1823.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5-53uVuoyTMhX21A",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1616.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5_AXuVuoyTMhX21C",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail3002.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5_j3uVuoyTMhX21U",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail3039.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5_yQuVuoyTMhX21d",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1136.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5zbquVuoyTMhX20C",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail166.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5zfsuVuoyTMhX20E",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail2767.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt59jQuVuoyTMhX20p",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail2852.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5_PpuVuoyTMhX21J",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1392.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt58YguVuoyTMhX20N",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail603.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5_38uVuoyTMhX21h",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail416.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt5-JFuVuoyTMhX20y",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail896.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt6B1NuVuoyTMhX22i",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail846.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt6B3vuVuoyTMhX22k",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1214.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt6B90uVuoyTMhX22o",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail1536.png"
            }
        }, {
            "_index": "geotiff_test",
            "_type": "geometa",
            "_id": "AVtt6COkuVuoyTMhX22y",
            "_score": 1.0,
            "_source": {
                "thumbnail": "thumbnail246.png"
            }
        }]
    }
}

然而，当我运行这样的查询时，它什么也没有返回：

curl -X POST http://localhost:9200/geotiff_test/geometa/_search -d '{
    "query": {
        "term": {
            "thumbnail": "thumbnail1536.png"
        }
    }
}'

这是结果：

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 5,
        "successful": 5,
        "failed": 0
    },
    "hits": {
        "total": 0,
        "max_score": null,
        "hits": []
    }
}

如果这是 Solr，我要做的就是运行这个简单的查询：thumbnail:"thumbnail1536.png"

谁能告诉我这里出了什么问题？

【问题讨论】：

标签： java elasticsearch lucene

【解决方案1】：

确切的术语不匹配，因为您的文档字段 thumbnail 已使用 standard 分析器进行分析并将其存储为 thumbnail1536 和 png。

在 Elasticsearch 中，text (full-text) 和 keyword (exact-term) 有不同的查询。你写的属于后一类。

如果您运行以下full-text 查询，您将获得所需的结果：

curl -X POST http://localhost:9200/geotiff_test/geometa/_search -d '{
    "query": {
        "match": {
            "thumbnail": "thumbnail1536.png"
        }
    }
}'

但当您尝试使用term 搜索exact-term 时，首选查询。

curl -X POST http://localhost:9200/geotiff_test/geometa/_search -d '{
    "query": {
        "term": {
            "thumbnail.keyword": "thumbnail1536.png"
        }
    }
}'

注意：这里的.keyword 是keyword 版本的thumbnail 字段。

虽然两者产生相同的结果，但上述查询比前一个更有效。

【讨论】：

【解决方案2】：

这取决于您的字段是如何映射/键入的。请参考来自弹性搜索网站的link。

请注意，您可以更改映射以更好地满足您的需求。

【讨论】：

我真的是 ES 新手。所以我不确定为什么这甚至很重要，因为在 Solr 中，该查询将针对字符串或文本字段。