在Elasticsearch中按数组索引对搜索结果进行排序

Question

I have records like that:

// tags vary in order within array
{
    name : 'Karl',
    tags : [
        'java',
        'html',
        'javascript'
    ]
},
{
    name : 'John',
    tags : [
        'html',
        'java',
        'javascript'
    ]
}

I run a bool query on tags:

"query" : {
    "bool" : {
        "must" : [
            {
                "term" : "java"
            }
        ]
    }
}

I want Karl to be the first search result, because 'java' has a lower index in his tags array. Unfortunately my query doesn't care about the index, overall results are ok, but order of results seems to be random.

How can I force Elasticsearch to consider the array index?

thx!

Answer 1

If you need this information, then you're going to have to store the index of each element within that element:

{
    name : 'Karl',
    tags : [
        'java',
        'html',
        'javascript'
    ],
    index : 0
},
{
    name : 'John',
    tags : [
        'html',
        'java',
        'javascript'
    ],
    index : 1
}

Then you can sort on this index subfield:

"query" : {
    "bool" : {
        "must" : [
            {
                "term" : "java"
            }
        ]
    },
    "sort" : [
        "arrayFieldName.index" : "asc"
    ]
}