Elasticsearch查询词

Question

我正在尝试一个标题或正文为“ prueba”的课程：

查询：

{
    "query": {
        "filtered": {
            "query" : {
                "multi_match": {
                    "query": "prueba",
                    "fields": ["title","body"]
                }
            }
        }
    }
}

结果：

{
"_index": "content",
"_type": "comment_thread",
"_id": "5c3c79298115f61cc2000000",
"_score": 1.4054651,
"_source": {
"_id": "5c3c79298115f61cc2000000",
"body": "Hola esto es una prueba",
"commentable_id": "course",
"context": "course",
"course_id": "course-v1:edx+CC101+2019_T1",
}

Okey，太完美了。现在，我想进行相同的搜索，但要添加确切的course_id。所以：

查询：

{
    "query": {
        "filtered": {
            "query" : {
                "multi_match": {
                    "query": "prueba",
                    "fields": ["title","body"]
                }
            },
            "filter": {
                "bool": {
                    "must": {
                        "term" : { "course_id": "course-v1:edx+CC101+2019_T1" }
                    }
                }
            }
        }
    }
}

结果：0次点击

但是如果我放"term" : { "course_id": "course" }，请返回课程。...

这是怎么回事？

映射：

"course_id": {
    "type": "string"
},

ElasticSearch版本：

{
  "status" : 200,
  "name" : "MN-E (Ultraverse)",
  "cluster_name" : "elasticsearch",
  "version" : {
    "number" : "1.5.2",
    "build_hash" : "62ff9868b4c8a0c45860bebb259e21980778ab1c",
    "build_timestamp" : "2015-04-27T09:21:06Z",
    "build_snapshot" : false,
    "lucene_version" : "4.10.4"
  },
  "tagline" : "You Know, for Search"
}