This API is used to search content in Elasticsearch. A user can search by sending a get request with query string as a parameter or they can post a query in the message body of post request. Mainly all the search APIS are multi-index, multi-type.
Multi-Index
Elasticsearch allows us to search for the documents present in all the indices or in some
specific indices. For example, if we need to search all the documents with a name that contains central, we can do as shown here −
GET /_all/_search?q=city:paprola
On running the above code, we get the following response −
{ "took" : 33, "timed_out" : false, "_shards" : { "total" : 7, "successful" : 7, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 1, "relation" : "eq" }, "max_score" : 0.9808292, "hits" : [ { "_index" : "schools", "_type" : "school", "_id" : "5", "_score" : 0.9808292, "_source" : { "name" : "Central School", "description" : "CBSE Affiliation", "street" : "Nagan", "city" : "paprola", "state" : "HP", "zip" : "176115", "location" : [ 31.8955385, 76.8380405 ], "fees" : 2200, "tags" : [ "Senior Secondary", "beautiful campus" ], "rating" : "3.3" } } ] } }
URI Search
Many parameters can be passed in a search operation using Uniform Resource Identifier −
S.No | Parameter & Description |
---|---|
1 |
Q This parameter is used to specify query string. |
2 |
lenient This parameter is used to specify query string.Format based errors can be ignored by just setting this parameter to true. It |
3 |
fields This parameter is used to specify query string. |
4 |
sort We can get sorted result by using this parameter, the possible values for this parameter is fieldName, fieldName:asc/fieldname:desc |
5 |
timeout We can restrict the search time by using this parameter and response only contains the hits in that specified time. By default, there is no timeout. |
6 |
terminate_after We can restrict the response to a specified number of documents for each shard, upon reaching which the query will terminate early. By default, there is no terminate_after. |
7 |
from The starting from index of the hits to return. Defaults to 0. |
8 |
size It denotes the number of hits to return. Defaults to 10. |
Request Body Search
We can also specify query using query DSL in request body and there are many examples already given in previous chapters. One such example is given here −
POST /schools/_search { "query":{ "query_string":{ "query":"up" } } }
On running the above code, we get the following response −
{ "took" : 11, "timed_out" : false, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : { "value" : 1, "relation" : "eq" }, "max_score" : 0.47000363, "hits" : [ { "_index" : "schools", "_type" : "school", "_id" : "4", "_score" : 0.47000363, "_source" : { "name" : "City Best School", "description" : "ICSE", "street" : "West End", "city" : "Meerut", "state" : "UP", "zip" : "250002", "location" : [ 28.9926174, 77.692485 ], "fees" : 3500, "tags" : [ "fully computerized" ], "rating" : "4.5" } } ] } }