Connecting to Couchbase

Couchbase is a NoSQL document-oriented database. Use Analytics's data connector to import your organization's Couchbase data.

Before you start

To connect to Couchbase, you must gather the following:

• at least one node in your Couchbase instance with the query and index services enabled
• the database server's host name
• the correct connection port
• appropriate credentials for your chosen authentication method

  If your Couchbase instance requires authentication, you must provide either a JSON string or a JSON file that specifies the name and password for one or more buckets> For more information, see JSON authentication format.

• a valid SSL certificate if connecting over SSL

For help gathering the connection prerequisites, contact the Couchbase administrator in your organization. If your administrator cannot help you, you or your administrator should contact Couchbase Support.

Create a Couchbase connection

1. From the Analytics main menu, select Import > Database and application.
2. From the New Connections tab, in the ACL Connectors section, select Couchbase.

   Tip

   You can filter the list of available connectors by entering a search string in the Filter connections box. Connectors are listed alphabetically.

3. In the Data Connection Settings panel, enter the connection settings and at the bottom of the panel, click Save and Connect.

   You can accept the default Connection Name, or enter a new one.

The connection for Couchbase is saved to the Existing Connections tab. In the future, you can reconnect to Couchbase from the saved connection.

Once the connection is established, the Data Access window opens to the Staging Area and you can begin importing data. For help importing data from Couchbase, see Import data using the Data Access window .

Querying the Couchbase instance

JSON authentication format

[{"user" : "userName1", "pass" : "passWord1"},
{"user" : "userName2", "pass" : "passWord2"}]

SQL queries vs N1QL API calls

The connector uses normal SQL queries against the Couchbase Server, translating standard SQL-92 queries into equivalent N1QL client API calls. This translation allows standard queries to run against your Couchbase Server instance. If a query cannot be fully translated, then the translated parts of the query are passed down as one or more N1QL queries to the Couchbase Server instance for processing while the untranslated parts of the query are processed by the Connector.

Schema definition

Couchbase is able to store data that follows different rules of data typing and structure compared to traditional relational tables and columns. Couchbase data is organized into buckets and documents, which can contain nested arrays or arrays of differently typed elements. This data needs to be mapped to a relational form. To achieve this, the connector generates a schema definition that maps the Couchbase data to an ODBC-compatible format.

When you connect to a database that does not already have the necessary schema definition, the connector automatically generates one by doing the following:

1. For each document type identified in the database, the connector samples data from multiple documents to detect the structure of the data.
2. The connector organizes all the documents into collections based on their type, and saves these collections as part of the schema definition. Using the schema definition, the driver exposes collections as tables.
3. For each array detected in the database, the connector generates a virtual table to expand the data, and saves these virtual tables as part of the schema. Using the schema, the driver exposes virtual tables as normal tables.
4. The connector defines a Couchbase data type for each column and maps each Couchbase data type to the SQL data type that is best able to represent the greatest number of values.

Base tables

Base tables represent data from collections of Couchbase documents. Documents appear as rows, and all attributes that are not arrays appear as columns. In each base table, the connector creates a primary key column named PK that identifies which Couchbase document each row comes from.

In the connector, the name of the base table is the document type that it represents. In Couchbase, the name of the base table is the bucket that the data comes from.

Virtual tables

Virtual tables provide support for arrays. Each virtual table contains the data from one array, and each row in the table represents an element from the array. If an element contains an array, then the connector creates additional virtual tables as needed to expand the nested data.

In each virtual table, the connector creates a primary key column name that identifies the document that the array comes from and references the column from the related base table. The connector also creates an index column (with the suffix _IDX in its name) to indicate the position of the element within the array.

{
  "Type": "Customer",
  "Name": "John Doe",
  "SavedAddresses": ["123 Main St.", "456 1st Ave"]
}

{
  "Type": "Order",
  "CustomerID":"Customer_123221",
  "CreditCard":
    {
      "Type":"Visa",
       "CardNumber":"4111 1111 1111 1111",
       "Expiry":"12/12",
       "CVN":"123"
    },
  "Items":
    [
      {"ItemID":89123, "Quantity":1},
      {"ItemID":92312, "Quantity":5}
    ]
}