Does anyone know if it's possible to custom sort in elasticsearch?
I have a sort on the category field. Which groups all of the records together by category. This works great.
However could you then give the sort a list e.g cars, books, food.
It would then show the cars first, then books and finally food?
You can use a function_score query, something like this:
{
"query": {
"function_score": {
"query": { "match_all": {} },
"boost": "5",
"functions": [
{
"filter": { "match": { "category": "cars" } },
"weight": 100
},
{
"filter": { "match": { "category": "books" } },
"weight": 50
},
{
"filter": { "match": { "category": "food" } },
"weight": 1
}
],
"score_mode": "max",
"boost_mode": "replace"
}
}
}
Where you, of course, put whichever query you are using now instead of the match_all query, and leave off the sort (the default is by score, which is what you want here).
This is replacing the score elasticsearch normally generates, with a custom score for each category. You could experiment with other boost_mode in order to have a reasonable ranking within the categories. In case you need to understand what is happening with the scoring, you can add "explain": true to the query at the top level.
You can use custom script for your own scoring.
More details at in Script Based Sorting section: https://www.elastic.co/guide/en/elasticsearch/reference/5.5/search-request-sort.html
