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Asked: 2026-05-28T06:08:05+00:00

I recently rewrote a Java EE web application (running on a MySQL database) to

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I recently rewrote a Java EE web application (running on a MySQL database) to Rails 3.1. The problem now is that the database model of the new application is not the same as the old one because I added, removed and renamed some attributes. The database table names are also different.

Is there a way of migrating this data? The only way I can imagine to do this is writing a stored procedure with many ALTER TABLE and CREATE TABLE statements to update the database to the new model.

Thanks in advanced.

Solution:

I finally used INSERT..SELECT statements in a mysql stored procedure to migrate the data. INSERT INTO new_schema.new_table SELECT FROM old_schema.old_table. I am now considering making a Rake task to call that procedure and doing other stuff.

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1 Answer

  1. Editorial Team

    The only way is to write a script that take the data from the old db and insert thme in the new db. Or you can in some way to connect to the two databases and then make some select and insert query, something like 

     insert into new_db.table as select old_db.table.field1, ....

    or

     insert into new_db.table (field_1, field_2) values (select old_db.table.field_1, ...)

    In any way, is a manual process, also if can be automated to some extend with a script

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