Identifiers: Default and Custom

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pseudocode
const docID = await ditto.store.collection('people').upsert({
  name: 'Susan',
  age: 31,
})
console.log(docID) // Auto-generated UUID is: "507f191e810c19729de860ea"
const docID = await ditto.store.collection('people').upsert({
  name: 'Susan',
  age: 31,
})
console.log(docID) // Auto-generated UUID is: "507f191e810c19729de860ea"
﻿
Following are the main features and qualities associated with the _id field: 
Document Identification: The document _id field serves as the primary key identifying the document in Ditto. For more information, see Primary key﻿, as follows. 

Customizable Primary Key: If preferred, you can customize the primary key as a string or JSON blob object. For more information, see Custom Configuration﻿.

Retrieval by _id: Using the Find By ID method, you can fetch a document by its primary key. For more information, see Fetching a Document by _id﻿.
Primary Key
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For more information, see Custom Configurations﻿ , as follows.
Custom Configurations
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Supplying a String ID
The following snippet demonstrates creating a new document assigned the string value 123abc.
pseudocode
Curl
const docID = await ditto.store.collection('cars').upsert({
  _id: '123abc',
  name: 'Susan',
  age: 31,
})

console.log(docID) // "123abc"
const docID = await ditto.store.collection('cars').upsert({
  _id: '123abc',
  name: 'Susan',
  age: 31,
})

console.log(docID) // "123abc"
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Forming a Composite Key
The decision to opt for a composite key depends on your specific use case. Following are typical use cases for forming a composite key:
To implement additional logic to handle (or prevent) duplicate writes.

To simplify queries and enhance efficiency in the querying process.
To form a composite key, when calling Upsert to create a new document, pass the fields you want to combine to form the new primary key in an embedded map structure.
The following snippet demonstrates combining the user_id and work_id fields to form the 123abc780 composite key:
pseudocode
Curl
const docID = await ditto.store.collection('cars').upsert({
 _id: {
    user_id: "123abc",
    work_id: 789
  }
})

console.log(docID) // "123abc789"
const docID = await ditto.store.collection('cars').upsert({
 _id: {
    user_id: "123abc",
    work_id: 789
  }
})

console.log(docID) // "123abc789"
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Fetching a Document by _id
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pseudocode
const document = await ditto.store
.collection("cars")
.findById("123456")
const document = await ditto.store
.collection("cars")
.findById("123456")
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Updated 11 Mar 2024
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Fields and Key-Values
Collections