Data Sync

• Critical for enabling offline-first mobile app

• The two critical aspects enabling this is:

1. Ability to locally store data on the device so it is always available to the user, whether online or offline

2. Ability to sync data to the cloud so it is available to the users on other devices when online.

Data Sync

Query

• The query service supports the querying of data  ( N1QL query language)

The basic N1QL query : 

SELECT - The fields of each document to return

FROM - The data bucket in which to look

WHERE -The conditions that the document must satisfy 

Query

Query

Data in Couchbase Server is stored in the form of documents, not row/columns

String matching can be accomplished using LIKE operator in the WHERE clause.

Example :  % - Matches zero/more characters

Query

Filter based on arrays nested inside the document.

Using ANY/EVERY - SATISFIES construct.

Example :  Expression after ANY clause allows us to assign name to an element in the array that we searching through. SATIESFIES - to specify filter condition

Query