How to use nested in Ealsticsearch 7.10 - elasticsearch

Question

Followings are the steps on how using nested field in elastersearch.
First step:
curl -XPUT 'localhost:9200/my_index/my_type/1?pretty' -d'
{
"group" : "fans",
"user" : [ // 1
{
"first" : "John",
"last" : "Smith"
},
{
"first" : "Alice",
"last" : "White"
}
]
}'
Second step:
curl -XPUT 'localhost:9200/my_index?pretty' -d'
{
"mappings": {
"my_type": {
"properties": {
"user": {
"type": "nested" // 1
}
}
}
}
}'
Before i copy the code, i have delete all the index on my machine.
However, after running step 2, something went woring like the following .
{
"error" : {
"root_cause" : [
{
"type" : "resource_already_exists_exception",
"reason" : "index [my_index/yHhgr8iEQqGnHo5Ugex2dA] already exists",
"index_uuid" : "yHhgr8iEQqGnHo5Ugex2dA",
"index" : "my_index"
}
],
"type" : "resource_already_exists_exception",
"reason" : "index [my_index/yHhgr8iEQqGnHo5Ugex2dA] already exists",
"index_uuid" : "yHhgr8iEQqGnHo5Ugex2dA",
"index" : "my_index"
},
"status" : 400
}
I really don't konw what to do about this.(I have also tried create nested field first. It also went wrong)
I'm new to elastersearch, really need help. Thankyou very mutch!!!

Answer 1

Since you are using Elasticsearch version 7.10, you cannot add the mapping type in the index mapping definition. Refer to this to know more about the removal of mapping types.
You can not change the mapping of an index that already exists, you need to delete it and index the data with the new mapping, or reindex into a new index with the new mapping.
You need to first create the index with the following mapping:
PUT /my_index
{
"mappings": {
"properties": {
"user": {
"type": "nested" // 1
}
}
}
}
And then index the documents into the index. Refer to this official documentation, to know more about nested type.
PUT /my_index/_doc/1
{
"group" : "fans",
"user" : [ // 1
{
"first" : "John",
"last" : "Smith"
},
{
"first" : "Alice",
"last" : "White"
}
]
}