Connect to and Query CSV Data in QlikView over ODBC
The CData ODBC drivers expand your ability to work with data from more than 200 data sources. QlikView is a business discovery platform that provides self-service BI for all business users in an organization. This article outlines simple steps to connect to CSV data using the CData ODBC driver and create data visualizations in QlikView.
The CData ODBC drivers offer unmatched performance for interacting with live CSV data in QlikView due to optimized data processing built into the driver. When you issue complex SQL queries from QlikView to CSV, the driver pushes supported SQL operations, like filters and aggregations, directly to CSV and utilizes the embedded SQL engine to process unsupported operations (often SQL functions and JOIN operations) client-side. With built-in dynamic metadata querying, you can visualize and analyze CSV data using native QlikView data types.
Connect to CSV as an ODBC Data Source
If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.
Connecting to Local or Cloud-Stored (Box, Google Drive, Amazon S3, SharePoint) CSV Files
CData Drivers let you work with CSV 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 CSV file(s) within Amazon S3, set the URI property to the URI of the Bucket and Folder where the intended CSV 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 CSV file(s) within Box, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect to Box.
Dropbox
To connect to CSV file(s) within Dropbox, set the URI proprerty to the URI of the folder that includes the intended CSV 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 CSV file(s) within SharePoint with SOAP Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. Set User, Password, and StorageBaseURL.
SharePoint Online REST
To connect to CSV file(s) within SharePoint with REST Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. StorageBaseURL is optional. If not set, the driver will use the root drive. OAuth is used to authenticate.
Google Drive
To connect to CSV file(s) within Google Drive, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect and set InitiateOAuth to GETANDREFRESH.
When you configure the DSN, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.
Populate a Chart with CSV Data
The steps below supply the results of an SQL query to a visualization in QlikView. In this article, you will create a bar chart with the query below:
SELECT City, SUM(TotalDue) FROM Customer GROUP BY City
- Click File -> Edit Script (or click the Edit Script button in the Toolbar).
- On the Data tab, select ODBC in the Database menu and click Connect.
- Select the DSN (CData CSV Sys) in the resulting dialog.
A command like the following is generated:
ODBC CONNECT TO [CData CSV Sys];
- Enter the SQL query directly into the script with the SQL command (or click Select to build the query in the SELECT statement wizard).
SQL SELECT City, SUM(TotalDue) FROM Customer GROUP BY City;
Where possible, the SQL operations in the query, like filters and aggregations, will be pushed down to CSV, while any unsupported operations (which can include SQL functions and JOIN operations) will be managed client-side by the CData SQL engine embedded in the driver.
- Close the script editor and reload the document to execute the script.
- Click Tools -> Quick Chart Wizard. In the wizard, select the chart type. This example uses a bar chart. When building the chart, you have access to the fields from CSV, typed appropriately for QlikView, thanks to built-in dynamic metadata querying.
- When defining Dimensions, select City in the First Dimension menu.
- When defining Expressions, click the summary function you want and select TotalDue in the menu.
Finish the wizard to generate the chart. The CData ODBC Driver for CSV connects to live CSV data, so the chart can be refreshed to see real-time changes. Live connections are possible and effective, thanks to the high-performance data processing native to CData ODBC Drivers.