elasticsearch cmd2

Introducing the Query Language
Going back to our last example, we executed this query:

GET /bank/_search
{
  "query": { "match_all": {} }
}

In addition to the  query  parameter, we also can pass other parameters to influence the search results. In the example in the section above we passed in  sort , here we pass in  size :

GET /bank/_search
{
  "query": { "match_all": {} },
  "size": 1
}

Note that if  size  is not specified, it defaults to 10.
This example does a  match_all  and returns documents 10 through 19:

GET /bank/_search
{
  "query": { "match_all": {} },
  "from": 10,
  "size": 10
}

This example does a  match_all  and sorts the results by account balance in descending order and returns the top 10 (default size) documents.

GET /bank/_search
{
  "query": { "match_all": {} },
  "sort": { "balance": { "order": "desc" } }
}

 
 

Executing Searches

This example shows how to return two fields,  account_number  and  balance  (inside of  _source ), from the search:

GET /bank/_search
{
  "query": { "match_all": {} },
  "_source": ["account_number", "balance"]
}

 
Now let’s move on to the query part. Previously, we’ve seen how the  match_all  query is used to match all documents. Let’s now introduce a new query called the  match  query, which can be thought of as a basic fielded search query (i.e. a search done against a specific field or set of fields).
This example returns the account numbered 20:

GET /bank/_search
{
  "query": { "match": { "account_number": 20 } }
}

 
This example returns all accounts containing the term "mill"in the address:

GET /bank/_search
{
  "query": { "match": { "address": "mill" } }
}

 
Let’s now introduce the  bool  query. The  bool  query allows us to compose smaller queries into bigger queries using boolean logic.
This example composes two  match  queries and returns all accounts containing "mill"and "lane"in the address:

GET /bank/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "address": "mill" } },
        { "match": { "address": "lane" } }
      ]
    }
  }
}

 
In the above example, the  bool must  clause specifies all the queries that must be true for a document to be considered a match.
In contrast, this example composes two  match  queries and returns all accounts containing "mill"or "lane"in the address:

GET /bank/_search
{
  "query": {
    "bool": {
      "should": [
        { "match": { "address": "mill" } },
        { "match": { "address": "lane" } }
      ]
    }
  }
}

 
This example composes two  match  queries and returns all accounts that contain neither "mill"nor "lane"in the address:

GET /bank/_search
{
  "query": {
    "bool": {
      "must_not": [
        { "match": { "address": "mill" } },
        { "match": { "address": "lane" } }
      ]
    }
  }
}

 
We can combine  must ,  should , and  must_not  clauses simultaneously inside a  bool  query. Furthermore, we can compose  bool  queries inside any of these  bool  clauses to mimic any complex multi-level boolean logic.
This example returns all accounts of anybody who is 40 years old but doesn’t live in ID(aho):

GET /bank/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "age": "40" } }
      ],
      "must_not": [
        { "match": { "state": "ID" } }
      ]
    }
  }
}