How to correct paging by using top and skip in Azure Search? - azure

Question

According to this document Total hits and Page Counts, if I want to implements paging, I should combine skip and top in my query.
The following is my POST query
{
"count": true ,
"search": "apple",
"searchFields": "content",
"select": "itemID, content",
"searchMode": "all",
"queryType":"full",
"skip": 100,
"top":100
}
It should return something like from 100 --> 200
{
"#odata.context": "https://example.search.windows.net/indexes('example-index-')/$metadata#docs(*)",
"#odata.count": 1611,
"#search.nextPageParameters": {
"count": true,
"search": "apple",
"searchFields": "content",
"select": "itemID, content",
"searchMode": "all",
"queryType": "full",
"skip": 200
},
But it just return top 100 , not paging offset to 100
"#odata.context": "https://example.search.windows.net/indexes('example-index')/$metadata#docs(*)",
"#odata.count": 1611,
Is there any thing I should setup?

Answer 1

The short answer of how to implement paging (from this article): Set top to your desired page size, then increment skip by that page size on every request. Here is an example of how that would look with the REST API using GET:
GET /indexes/onlineCatalog/docs?search=*$top=15&$skip=0
GET /indexes/onlineCatalog/docs?search=*$top=15&$skip=15
GET /indexes/onlineCatalog/docs?search=*$top=15&$skip=30
The REST API documentation also covers how to implement paging, as well as the true purpose of #odata.nextLink and #search.nextPageParameters (also covered in this related question).
Quoting from the API reference:
Continuation of Partial Search Responses
Sometimes Azure Search can't return all the requested results in a single Search response. This can happen for different reasons, such as when the query requests too many documents by not specifying $top or specifying a value for $top that is too large. In such cases, Azure Search will include the #odata.nextLink annotation in the response body, and also #search.nextPageParameters if it was a POST request. You can use the values of these annotations to formulate another Search request to get the next part of the search response. This is called a continuation of the original Search request, and the annotations are generally called continuation tokens. See the example in Response below for details on the syntax of these annotations and where they appear in the response body.
The reasons why Azure Search might return continuation tokens are implementation-specific and subject to change. Robust clients should always be ready to handle cases where fewer documents than expected are returned and a continuation token is included to continue retrieving documents. Also note that you must use the same HTTP method as the original request in order to continue. For example, if you sent a GET request, any continuation requests you send must also use GET (and likewise for POST).
Note
The purpose of #odata.nextLink and #search.nextPageParameters is to protect the service from queries that request too many results, not to provide a general mechanism for paging. If you want to page through results, use $top and $skip together. For example, if you want pages of size 10, your first request should have $top=10 and $skip=0, the second request should have $top=10 and $skip=10, the third request should have $top=10 and $skip=20, and so on.

Answer 2

The follwing example is Get method without top.
GET Method
https://example.search.windows.net/indexes('example-content-index-zh')/docs?api-version=2017-11-11&search=2018&$count=true&$skip=150&select=itemID
The Result:
{
"#odata.context": "https://example.search.windows.net/indexes('example-index-zh')/$metadata#docs(*)",
"#odata.count": 133063,
"value": [ //skip value ],
"#odata.nextLink": "https://example.search.windows.net/indexes('example-content-index-zh')/docs?api-version=2017-11-11&search=2018&$count=true&$skip=150"
}
No matter I use post or get, onces I add $top=# the #odata.nextLink will not show in result.
Finally, I figure out although #odata.nextLink or #search.nextPageParameters will not show. But the paging is working, I have to count myself.