CRUD in Elasticsearch

I briefly introduced Elasticsearch in play with elasticsearch. In this article, we still do some basic learning about how to perform CRUD in Elasticsearch? Suppose we are creating an application similar to Weibo. Let's call it kiwi first. Kiwi is composed of messages. In kiwi, a message is called a ksay

I briefly introduced Elasticsearch in play with elasticsearch. In this article, we still do some basic learning about how to perform CRUD in Elasticsearch? Suppose we are creating an application similar to Weibo. Let's call it kiwi first. Kiwi is composed of messages. In kiwi, a message is called a ksay

I briefly introduced Elasticsearch in play with elasticsearch. In this article, we still do some basic learning about how to perform CRUD in Elasticsearch?

Suppose we are creating an application similar to Weibo. Let's call it kiwi first. Kiwi is composed of messages.

In kiwi, messages are called ksay. There are two parts. One is the author (author), but the message itself (message ).

Create

Curl-x post http: // localhost: 9200/kiwi/ksay/-d' {"author": "rococojie", "message": "I am beautiful "}'

Return: {"_ index": "kiwi", "_ type": "ksay", "_ id": "aaX3P2LJSP-dDYVy0USv7Q", "_ version": 1, "created": true}

We noticed that elasticsearch does not generate IDS by default in auto-increment mode. Instead, a 22-bit URL-safe _ id is automatically generated. As in the previous example, the returned _ id is the aaX3P2LJSP-dDYVy0USv7Q. To use a custom _ id, perform the following operations:

Curl-x post http: // localhost: 9200/kiwi/ksay/1-d' {"author": "jerry", "message": "I hate Tom "}'

Return Value: {"_ index": "kiwi", "_ type": "ksay ","_ Id": "1", "_ Version": 1, "created": true}

Read

Here we only want to use the id value

Curl-x get http: // localhost: 9200/kiwi/ksay/1

Return Value: {"_ index": "kiwi", "_ type": "ksay", "_ id": "1", "_ version": 1, "found": true, "_ source": {"author": "jerry", "message": "I hate Tom "}}

If we want to return the original data

Curl-x get http: // localhost: 9200/kiwi/ksay/1/_ source

Return Value: {"author": "jerry", "message": "I hate Tom "}

Curl-x get http: // localhost: 9200/kiwi/ksay/10000

{"_ Index": "kiwi", "_ type": "ksay", "_ id": "10000", "found": false }, the stored ksay is not found.

Update

Curl-x put http: // localhost: 9200/kiwi/ksay/1-d' {"author": "jerry", "message": "I love Tom "}'

Return Value: {"_ index": "kiwi", "_ type": "ksay", "_ id": "1", "_ version": 2, "created": false}

We noticed that the _ version here is changed to 2, and the knowledge has changed because of ksay. The return value of created is false, indicating that no new document is created, but the document is updated.

Although Elasticsearch supports document updates, we need to know that the documents stored in Elasticsearch are immutable ). This so-called update is actually an illusion. Inside Elasticsearch, we first mark the old data as "deleted ", then index the new data. (Retrieve-change-reindex)

Partial update

Curl-x post http: // localhost: 9200/kiwi/ksay/1/_ update-d' {"doc": {"message": "I hate Tom, again "}}'

Return Value: {"_ index": "kiwi", "_ type": "ksay", "_ id": "1", "_ version": 3}

"Doc" is the field to be updated. Elasticsearch will include the latest field "merge" to the original document. Here is the information of this ksay.

Curl-x get http: // localhost: 9200/kiwi/ksay/1

Return Value: {"_ index": "kiwi", "_ type": "ksay", "_ id": "1", "_ version": 3, "found": true, "_ source": {"author": "jerry", "message": "I hate Tom, again "}}

Delete

Curl-x delete http: // localhost: 9200/kiwi/ksay/1

Return Value: {"found": true, "_ index": "kiwi", "_ type": "ksay", "_ id": "1 ", "_ version": 4}

Try again to get ksay:

Curl-x get http: // localhost: 9200/kiwi/ksay/1

Return Value: {"_ index": "kiwi", "_ type": "ksay", "_ id": "1 ","Found": false}

Cannot be accessed. The value of found is false.

After learning the most basic CRUD of Elasticsearch, we can find some other users to play.