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
The connection-url
defines the connection information and parameters to pass
to the MySQL JDBC driver. The supported parameters for the URL are
available in the MySQL Developer Guide.
For example, the following connection-url
allows you to
configure the JDBC driver to interpret time values based on UTC as a timezone on
the server, and serves as a workaround for a known issue.
connection-url=jdbc:mysql://example.net:3306?serverTimezone=UTC
The connection-user
and connection-password
are typically required and
determine the user credentials for the connection, often a service user.
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.
General Configuration Properties#
Property Name |
Description |
Default |
---|---|---|
|
Name of the |
|
|
Name of the |
|
|
Match dataset and table names case-insensitively. |
|
|
Duration for which remote dataset and table names will be
cached. Set to |
|
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:
CREATE TABLE (CREATE TABLE AS is supported)