Read from NoSQL DB
The Read from NoSQL DB stage reads data from a database table as input to a dataflow. The stage supports MongoDB and Couchbase database (version 5.x and above).
General Tab
Field Name | Description |
---|---|
Connection |
Select the required database connection from the dropdown list. The options displayed are based on the connections defined in Spectrum Management Console. To add a new connection, see Connecting to NoSQL. To modify an existing connection, select and open it from the list of connections on the Connections page of Spectrum Management Console, make the required updates, and click the Save button. |
Table/View | Specifies the collection or view in the database that you want to query. Note: While the
term Table/View is used in the user interface, MongoDB calls it a
collection, and Couchbase calls it a view. |
Schema File | Click the Browse button (...) to select a JSON Schema file. This file is optional. Fields in the fields tab can be regenerated either using the schema file or database table/view. To clear the selected file path, click Clear. Note: Fields will always be generated using the schema file if one is selected. |
Where | Enter the required filter criteria, if any, using MongoDB syntax, to fetch specific
records. Leave the field blank if no filter criteria is required. This syntax is for a clause with an equal to operator:
You can join multiple clauses using the required operators. For a list of the
supported operators in the For example, to fetch records where the value of the column
Attention: Ensure you do not include the keyword
where in this
field.Note: Currently, this field is visible only on selecting a MongoDB
connection. |
Ignore Absent Fields | Fields defined in the schema, if not present in the actual record will not flow to the next stage if this option is selected. Note: If you do not enable this option, fields that are not present in the database table or view, are added and processed with the value as NULL. |
Preview | Displays the records from the selected table. Note: For MongoDB data sources, clicking
Preview shows the filtered records, if one or more
where clauses have been entered in the Where field.
If no where clause has been entered, the preview displays all the records.Note: For
Couchbase data sources, clicking Preview also displays the added
_id field containing the key. If the record already has an
_id field, then the added _id field overwrites the
pre-existing one at the time of previewing the fields. |
Expand All | Expands the items in the preview tree. |
Collapse All | Collapses the items in the preview tree. |
Fields Tab
The Fields tab allows you to select the data that you want to pass to the next stage. For more information, see Defining Fields in a NoSQL Database