I want to query data from two different MySQL databases to a new MySQL database.
I have two databases with a lot of irrelevant data and I want to create what can be seen as a data warehouse where only relevent data should be present coming from the two databases.
As of now all data gets sent to the two old databases, however I would like to have scheduled updating so the new database is up to speed. There is a key between the two databases so in best case I would like all data to be present in one table however this is not crucial.
I have done similar work with Logstash and ES, however I do not know how to do it when it comes to MySQL.
Best way to do that is create a ETL process with Pentaho Data Integrator or any ETL tool. Where your source will be two different databases, in the transformation part you can remove or add any business logic then load those data into new database.
If you create this ETL you can schedule it once a day so that your database will be up to date.
If you want to do this without an ETL than your database must be in same host. Than you can just add database name just before table name in query. like SELECT * FROM database.table_name