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URL: https://www.cdata.com/kb/tech/xml-jdbc-apache-nifi-batch-operations.rst

⇱ Perform Batch Operations with XML Data in Apache NiFi

Perform Batch Operations with XML Data in Apache NiFi

👁 Jerod Johnson
Jerod Johnson
Director, Technology Evangelism
Connect to XML data and perform batch operations in Apache NiFi using the CData JDBC Driver.

Apache NiFi supports powerful and scalable directed graphs of data routing, transformation, and system mediation logic. When paired with the CData JDBC Driver for XML, NiFi can work with live XML data. This article shows how to read data from a CSV file and perform batch operations (INSERT/UPDATE/DELETE) using the CData JDBC Driver for XML data in Apache NiFi (version 1.9.0 or later).

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live XML data. When you issue complex SQL queries to XML, the driver pushes supported SQL operations, like filters and aggregations, directly to XML and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze XML data using native data types.

Generate a JDBC URL

We need a JDBC URL to connect to XML data from Apachi NiFi.

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the XML JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

		java -jar cdata.jdbc.xml.jar

Fill in the connection properties and copy the connection string to the clipboard.

Connecting to Local or Cloud-Stored (Box, Google Drive, Amazon S3, SharePoint) XML Files

CData Drivers let you work with XML files stored locally and stored in cloud storage services like Box, Amazon S3, Google Drive, or SharePoint, right where they are.

Setting connection properties for local files

Set the URI property to local folder path.

Setting connection properties for files stored in Amazon S3

To connect to XML file(s) within Amazon S3, set the URI property to the URI of the Bucket and Folder where the intended XML files exist. In addition, at least set these properties:

  • AWSAccessKey: AWS Access Key (username)
  • AWSSecretKey: AWS Secret Key

Setting connection properties for files stored in Box

To connect to XML file(s) within Box, set the URI property to the URI of the folder that includes the intended XML file(s). Use the OAuth authentication method to connect to Box.

Dropbox

To connect to XML file(s) within Dropbox, set the URI proprerty to the URI of the folder that includes the intended XML file(s). Use the OAuth authentication method to connect to Dropbox. Either User Account or Service Account can be used to authenticate.

SharePoint Online (SOAP)

To connect to XML file(s) within SharePoint with SOAP Schema, set the URI proprerty to the URI of the document library that includes the intended XML file. Set User, Password, and StorageBaseURL.

SharePoint Online REST

To connect to XML file(s) within SharePoint with REST Schema, set the URI proprerty to the URI of the document library that includes the intended XML file. StorageBaseURL is optional. If not set, the driver will use the root drive. OAuth is used to authenticate.

Google Drive

To connect to XML file(s) within Google Drive, set the URI property to the URI of the folder that includes the intended XML file(s). Use the OAuth authentication method to connect and set InitiateOAuth to GETANDREFRESH.

The property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

  • Document (default): Model a top-level, document view of your XML data. The data provider returns nested elements as aggregates of data.
  • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
  • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

See the Modeling XML Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)

Batch Operations (INSERT/UPDATE/DELETE) in Apache NiFi

The sample flow presented below is based on the following NiFi Processors:

  • ListFile - Retrieves a listing of files from the local filesystem and creates a FlowFile for each retrieved file.
  • FetchFile - Reads the content of the FlowFile received from the ListFile processor.
  • PutDatabaseRecord - Uses a specified RecordReader to input records from a flow file coming from the FetchFile processor. These records are translated to SQL statements and executed as a single transaction.
  • LogAttribute - Emits attributes of the FlowFile at the specified log level.

This is what our finished product looks like:

👁 NiFi GUI

Disclaimers

1. The column names of the CSV file must match the column names of the data source table records to be inserted/updated/deleted.

2. Apache NiFi versions earlier than 1.9.0 do not support the Maximum Batch Size property in the PutDatabaseRecord processor.

Configurations

In order to perform batch INSERT, UPDATE or DELETE, the NiFi Processors should be configured similar to the following:

  1. Configure the ListFile processor: Set the Input Directory property to the local folder path from where to pull the CSV files. Set the File Filter property to a regular expression to pick up only the files whose names match the expression. i.e., if the CSV file's full path is C:\Users\Public\Documents\InsertNiFi.csv, the properties should be configured like in the following image:
    2. 👁 config for ListFile
  2. Configure the FetchFile processor
    3. Leave the FetchFile processor's property configurations to their default values: 👁 config for FetchFile
  3. Configure the PutDatabaseRecord processor

      4. INSERT operation

      Configure the PutDatabaseRecord processor similar to the following in order to perform Batch INSERT Operations:

      👁 config for PutDatabaseRecord-INSERT
      👁 config for PutDatabaseRecord-INSERT
      • Set the Record Reader property to a CSV Reader Controller Service. Configure the CSV Reader Controller Service to match the format of your CSV file.
      • Set the Statement Type property to INSERT.
      • Set the Database Connection Pooling Service to the DBCPConnection Pool that holds the driver configuration. Please note that the driver should be configured to use Bulk API.
        Property Value
        Database Connection URL jdbc:xml:URI=C:/people.xml;DataModel=Relational;
        Database Driver Class Name cdata.jdbc.xml.XMLDriver
      • Set the Catalog Name property to the name of the catalog that your table is part of.
      • Set the Schema Name property to the name of the schema that your table is part of.
      • Set the Table Name property to the name of the table that you want to INSERT into.
      • Set the Maximum Batch Size property to the maximum number of records that you want to be included in a single batch. 👁 config for PutDatabaseRecord-INSERT

      UPDATE Operation

      Configure the PutDatabaseRecord processor similar to the following in order to perform Batch UPDATE Operations:

      • Set the Record Reader property to a CSV Reader Controller Service. Configure the CSV Reader Controller Service to match the format of your CSV file. 👁 config for PutDatabaseRecord-INSERT
        👁 config for PutDatabaseRecord-INSERT
      • Set the Statement Type property to UPDATE.
      • Set the Database Connection Pooling Service to the DBCPConnection Pool that holds the driver configuration. Please note that the driver should be configured to use Bulk API. Use the same Database Connection URL format as seen above.
      • Set the Catalog Name property to the name of the catalog that your table is part of.
      • Set the Schema Name property to the name of the schema that your table is part of.
      • Set the Table Name property to the name of the table that you want to UPDATE.
      • Set the Update Keys property to the name of the columns that are required for an UPDATE.
      • Set the Maximum Batch Size property to the maximum number of records that you want to be included in a single batch. 👁 config for PutDatabaseRecord-UPDATE

      DELETE Operation

      Configure the PutDatabaseRecord processor similar to the following in order to perform Batch DELETE Operations:

      • Set the Record Reader property to a CSV Reader Controller Service. Configure the CSV Reader Controller Service to match the format of your CSV file. 👁 config for PutDatabaseRecord-UPDATE
        👁 config for PutDatabaseRecord-UPDATE
      • Set the Statement Type property to DELETE.
      • Set the Database Connection Pooling Service to the DBCPConnection Pool that holds the driver configuration. Please note that the driver should be configured to use Bulk API. Use the same Database Connection URL format as seen above.
      • Set the Catalog Name property to the name of the catalog that your table is part of.
      • Set the Schema Name property to the name of the schema that your table is part of.
      • Set the Table Name property to the name of the table that you want to UPDATE.
      • In comparison to INSERT and UPDATE statement types, the DELETE operation does not expose a Maximum Batch Size property. However, the operations are still processed in batches. If not changed, the maximum number of records per batch is 2000, adhering to the default value. In order to change the value of the Maximum Batch Size used for DELETE operations, change the statement type to INSERT or UPDATE, then change the value of the Maximum Batch Size property, and click Apply Changes. Finally, reopen the processor's configuration, change the Statement Type back to DELETE, and click Apply Changes.
        • 👁 config for PutDatabaseRecord-DELETE
  4. Configure the LogAttribute processor

    Finally, configure the LogAttribute processor by specifying the Attributes that you would like to log or ignore, as well as the log level, based on your use case.

Free Trial & More Information

Download a free, 30-day trial of the CData JDBC Driver for XML and start working with your live XML data in Apache NiFi. Reach out to our Support Team if you have any questions.