Self type join in elasticsearch

[ducanh2110 (Anh Duc)]

Hi, I have a question about child-parent join in Elasticsearch, I have a real model like Category and Product.

"categoryRelations": {
"type": "join",
"eager_global_ordinals": true,
"relations": {
"category": [
"productContent",
"category"
]
}
}

and I design mapping in my index like that. My purpose here is category have child category, and in each category has its own product. Can i design like that or any suggestion for doing that? when I tried to put some data with relation category and parent it show exception: "DocValuesField "categoryRelations#category" appears more than once in this document (only one value is allowed per field)".

Thanks so much

[spinscale (Alexander Reelsen)]

Hey,

indeed, you cannot self join. If each product would contain the category it is in as an array (aka a multivalue), would that work as well? You might want to take a look at the path hierarchy tokenizer

--Alex

[ducanh2110 (Anh Duc)]

Thanks for your support. I will make your solution clearly. You mean that i will add one field to product that contains all category tree that product is belong to? Is that what you mean. Thanks

[spinscale (Alexander Reelsen)]

yes, that was what I meant.

[ducanh2110 (Anh Duc)]

Thanks I will try it tomorrow.