在Elasticsearch中更新多层嵌套文档

Question

Using Elasticsearch 1.7.1, I have the following document structure

"_source" : {
"questions" : {
    "defaultQuestion" : {           
        "tag" : 0,
        "gid" : 0,
        "rid" : 0,
        "caption" : "SRID",         
    },
    "tableQuestion" : {
        "rows" : [{
                "ids" : {                       
                    "answerList" : ["3547", "3548"],                        
                    "tag" : "0",
                    "caption" : "Accounts",                     
                },
                "name" : {                      
                    "answerList" : ["Some Name"],                       
                    "tag" : "0",
                    "caption" : "Name",                     
                }
            }
        ],
        "caption" : "BPI 1500541753537",
        "id" : 644251570,
        "tag" : ""
    }
},
"id" : "447722821"  
}

I want to add a new object in in questions.tableQuestion.rows. My current script is replacing the existing object with the new one. Kindly suggest how to append it instead. Following is my update script.

{ "update": {"_id": "935663867", "_retry_on_conflict" : 3} }
{ "script" : "ctx._source.questions += param1", "params" : {"param1" : {"tableQuestion": {"rows" : [ NEWROWOBJECT ]}  } }}

Answer 1

You can build the path with next nested fields, right to the rows property and then use += operator. It's also good to have a check if rows array is null and initialize it in this case.

Checked with ES 2.4, but should be similar for earlier versions:

POST http://127.0.0.1:9200/sample/demo/{document_id}/_update

{ 
    "script": {
        "inline": "if (ctx._source.questions.tableQuestion.rows == null) ctx._source.questions.tableQuestion.rows = new ArrayList(); ctx._source.questions.tableQuestion.rows += param1;",
        "params" : {
            "param1" : {
                            "ids": {
                                "answerList": [
                                    "478",
                                    "255"
                                ],
                                "tag": "2",
                                "caption": "My Test"
                            },
                            "name": {
                                "answerList": [
                                    "My Name"
                                ],
                                "tag": "1",
                                "caption": "My Demo"
                            }
                        }
        }
    }
}

For ES 5.x and Painless language the script is a bit different:

POST http://127.0.0.1:9200/sample/demo/{document_id}/_update

{ 
    "script": {
        "inline": "if (ctx._source.questions.tableQuestion.rows == null) { ctx._source.questions.tableQuestion.rows = new ArrayList();} ctx._source.questions.tableQuestion.rows.add(params.param1);",
        "params" : {
            "param1" : {
                            ...
            }
        }
    }
}

Update to the additional comment

If some part of the path is dynamic, you can also use parameters to build the path - with get(param_name) method - try this syntax (I removed the null check for simplicity):

{ 
    "script": {
        "inline": "ctx._source.questions.get(param2).rows += param1;",
        "params" : {
            "param2" : "6105243",
            "param1" : {
                            "ids": {
                                "answerList": [
                                    "478",
                                    "255"
                                ],
                                "tag": "2",
                                "caption": "My Test"
                            },
                            "name": {
                                "answerList": [
                                    "My Name"
                                ],
                                "tag": "1",
                                "caption": "My Demo"
                            }
                        }
        }
    }
}