The Altair Community is migrating to a new platform to provide a better experience for you. In preparation for the migration, the Altair Community is on read-only mode from October 28 - November 6, 2024. Technical support via cases will continue to work as is. For any urgent requests from Students/Faculty members, please submit the form linked here

Pre-joining

DocMusherDocMusher Member Posts: 333 Unicorn
edited November 2018 in Help
Hi,
How can I pre-join more than 2 tables in read database query?
Is somebody using a psql visual query builder within RM?
Sven

Answers

  • JEdwardJEdward RapidMiner Certified Analyst, RapidMiner Certified Expert, Member Posts: 578 Unicorn
    If you're using SQL the format of the join code is pretty straightforward

    SELECT *  FROM /* This selects all columns */
    table1
    INNER JOIN table2  /* Use LEFT JOIN or RIGHT JOIN if needed.
    ON table1.key1 = table2.key2  /* here you put in your key joins, use AND or OR to separate out different join rules.
    INNER JOIN table3  /* Use LEFT JOIN or RIGHT JOIN if needed.
    ON table1.key1 = table3.key2  /* You can also join to table2 if needed.


    This is standard SQL so the same query would work on Oracle, SQL Server, MySQL, PostgreSQL as you choose. 
Sign In or Register to comment.