11.4. MySQL Connector
The MySQL connector allows querying and creating tables in an external MySQL database. This can be used to join data between different systems like MySQL and Hive, or between two different MySQL instances.
Configuration
To configure the MySQL connector, create a catalog properties file in etc/catalog named, for example, mysql.properties, to mount the MySQL connector as the mysql catalog. Create the file with the following contents, replacing the connection properties as appropriate for your setup:
connector.name=mysql
connection-url=jdbc:mysql://example.net:3306
connection-user=root
connection-password=secret
Multiple MySQL Servers
You can have as many catalogs as you need, so if you have additional MySQL servers, simply add another properties file to etc/catalog with a different name (making sure it ends in .properties). For example, if you name the property file sales.properties, Presto will create a catalog named sales using the configured connector.
Querying MySQL
The MySQL connector provides a schema for every MySQL database. You can see the available MySQL databases by running SHOW SCHEMAS:
SHOW SCHEMAS FROM mysql;
If you have a MySQL database named web, you can view the tables in this database by running SHOW TABLES:
SHOW TABLES FROM mysql.web;
You can see a list of the columns in the clicks table in the web database using either of the following:
DESCRIBE mysql.web.clicks;
SHOW COLUMNS FROM mysql.web.clicks;
Finally, you can access the clicks table in the web database:
SELECT * FROM mysql.web.clicks;
If you used a different name for your catalog properties file, use that catalog name instead of mysql in the above examples.
MySQL Connector Limitations
The following SQL statements are not yet supported:
- INSERT
- DELETE
- ALTER TABLE
- CREATE TABLE (CREATE TABLE AS is supported)