How to create CSV federated tables in MySQL

You can use the SQL Gateway to configure a MySQL remoting service and set up federated tables for CSV data. The service is a daemon process that provides a MySQL interface to the CData ODBC Driver for CSV: After you have started the service, you can create a server and tables using the FEDERATED Storage Engine in MySQL. You can then work with CSV data just as you would local MySQL tables.

Connect to CSV Data

If you have not already done so, provide values for the required connection properties in the data source name (DSN). You can use the built-in Microsoft ODBC Data Source Administrator to configure the DSN. This is also the last step of the driver installation. See the "Getting Started" chapter in the help documentation for a guide to using the Microsoft ODBC Data Source Administrator to create and configure a DSN.

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.

Configure the SQL Gateway

See the SQL Gateway Overview to set up connectivity to CSV data as a virtual MySQL database. You will configure a MySQL remoting service that listens for MySQL requests from clients. The service can be configured in the SQL Gateway UI.

👁 Creating a MySQL Remoting Service in SQL Gateway (Salesforce is shown)

Create a FEDERATED Server and Tables for CSV Data

After you have configured and started the service, create a FEDERATED server to simplify the process of creating FEDERATED tables:

Create a FEDERATED Server

The following statement will create a FEDERATED server based on the ODBC Driver for CSV. Note that the username and password of the FEDERATED server must match a user account you defined on the Users tab of the SQL Gateway.

CREATE SERVER fedCSV
FOREIGN DATA WRAPPER mysql
OPTIONS (USER 'sql_gateway_user', PASSWORD 'sql_gateway_passwd', HOST 'sql_gateway_host', PORT ####, DATABASE 'CData CSV Sys');

Create a FEDERATED Table

To create a FEDERATED table using our newly created server, use the CONNECTION keyword and pass the name of the FEDERATED server and the remote table (Customer). Refer to the following template for the statement to create a FEDERATED table:

CREATE TABLE fed_customer (
 ...,
 city TYPE(LEN),
 totaldue TYPE(LEN),
 ...,
)
ENGINE=FEDERATED
DEFAULT CHARSET=latin1
CONNECTION='fedCSV/customer';

NOTE: The table schema for the FEDERATED table must match the remote table schema exactly. You can always connect directly to the MySQL remoting service using any MySQL client and run a SHOW CREATE TABLE query to get the table schema.

Execute Queries

You can now execute queries to the CSV FEDERATED tables from any tool that can connect to MySQL, which is particularly useful if you need to JOIN data from a local table with data from CSV. Refer to the following example:

SELECT 
 fed_customer.city, 
 local_table.custom_field 
FROM 
 local_table 
JOIN 
 fed_customer 
ON 
 local_table.foreign_city = fed_customer.city;