Access CSV Data in Mule Applications Using the CData JDBC Driver

The CData JDBC Driver for CSV connects CSV data to Mule applications enabling read functionality with familiar SQL queries. The JDBC Driver allows users to easily create Mule applications to backup, transform, report, and analyze CSV data.

This article demonstrates how to use the CData JDBC Driver for CSV inside of a Mule project to create a Web interface for CSV data. The application created allows you to request CSV data using an HTTP request and have the results returned as JSON. The exact same procedure outlined below can be used with any CData JDBC Driver to create a Web interface for the 200+ available data sources.

1. Create a new Mule Project in Anypoint Studio.
2. Add an HTTP Connector to the Message Flow.
3. Configure the address for the HTTP Connector.
4. Add a Database Select Connector to the same flow, after the HTTP Connector.
5. Create a new Connection (or edit an existing one) and configure the properties.
   • Set Connection to "Generic Connection"
   • Select the CData JDBC Driver JAR file in the Required Libraries section (e.g. cdata.jdbc.csv.jar).
   • Set the URL to the connection string for CSV

     The DataSource property must be set to a valid local folder name.

     Also, specify the IncludeFiles property to work with text files having extensions that differ from .csv, .tab, or .txt. Specify multiple file extensions in a comma-separated list. You can also set Extended Properties compatible with the Microsoft Jet OLE DB 4.0 driver. Alternatively, you can provide the format of text files in a Schema.ini file.

     Set UseRowNumbers to true if you are deleting or updating in CSV. This will create a new column with the name RowNumber which will be used as key for that table.

     Built-in Connection String Designer

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

     java -jar cdata.jdbc.csv.jar

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

   • Set the Driver class name to cdata.jdbc.csv.CSVDriver.
   • Click Test Connection.
6. Set the SQL Query Text to a SQL query to request CSV data. For example: SELECT City, SUM(TotalDue) FROM Customer GROUP BY City
7. Add a Transform Message Component to the flow.
8. Set the Output script to the following to convert the payload to JSON:

   %dw 2.0
   output application/json
   ---
   payload
           

9. To view your CSV data, navigate to the address you configured for the HTTP Connector (localhost:8081 by default): http://localhost:8081. The CSV data is available as JSON in your Web browser and any other tools capable of consuming JSON endpoints.

At this point, you have a simple Web interface for working with CSV data (as JSON data) in custom apps and a wide variety of BI, reporting, and ETL tools. Download a free, 30 day trial of the JDBC Driver for CSV and see the CData difference in your Mule Applications today.