How to create FTP federated tables in MySQL

You can use the SQL Gateway to configure a MySQL remoting service and set up federated tables for FTP data. The service is a daemon process that provides a MySQL interface to the CData ODBC Driver for FTP: 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 FTP data just as you would local MySQL tables.

Connect to FTP 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.

To connect to FTP or SFTP servers, specify at least RemoteHost and FileProtocol. Specify the port with RemotePort.

Set User and Password to perform Basic authentication. Set SSHAuthMode to use SSH authentication. See the Getting Started section of the data provider help documentation for more information on authenticating via SSH.

Set SSLMode and SSLServerCert to secure connections with SSL.

The data provider lists the tables based on the available folders in your FTP server. Set the following connection properties to control the relational view of the file system:

• RemotePath: Set this to the current working directory.
• TableDepth: Set this to control the depth of folders to list as views.
• FileRetrievalDepth: Set this to retrieve and list files recursively from the root table.

Stored Procedures are available to download files, upload files, and send protocol commands. See the Data Model chapter of the FTP data provider documentation for more information.

Configure the SQL Gateway

See the SQL Gateway Overview to set up connectivity to FTP 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.

Create a FEDERATED Server and Tables for FTP 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 FTP. 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 fedFTP
FOREIGN DATA WRAPPER mysql
OPTIONS (USER 'sql_gateway_user', PASSWORD 'sql_gateway_passwd', HOST 'sql_gateway_host', PORT ####, DATABASE 'CData FTP 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 (MyDirectory). Refer to the following template for the statement to create a FEDERATED table:

CREATE TABLE fed_mydirectory (
  ...,
  filesize  TYPE(LEN),
  filename  TYPE(LEN),
  ...,
)
ENGINE=FEDERATED
DEFAULT CHARSET=latin1
CONNECTION='fedFTP/mydirectory';

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 FTP 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 FTP. Refer to the following example:

SELECT 
  fed_mydirectory.filesize, 
  local_table.custom_field 
FROM 
  local_table 
JOIN 
  fed_mydirectory 
ON 
  local_table.foreign_filesize = fed_mydirectory.filesize;