It seems that whenever I change my models, Play Framework asks me to run a script that deletes my entire schema and recreates it. Obviously this won't work for production, so what is the proper way to handle this in production?
Note, I'm using ebean and Postgres, and hosting on heroku.
Unfortunately Ebean
can create only CREATE DDL
(and not UPDATE DDL
) (as answered on their group ), therefore you need to switch to manual evolutions ASAP.
some rules:
1.sql
evolution created by it 1.sql
and start to writing own evolutions with next numbers 2.sql
, 3.sql
etc. Try to place as many models/fields as possible before switching to manual evolutions. The biggest part will be done automatically by plugin. ALTERS
to existing tables/columns instead of DROP/CREATE, they should have both: Ups
and Downs
for each change. De facto sometimes it's just easier to modify DB structure with DB gui, anyway it works mainly for the single developer... when you need to share your code with other developers writing evolutions will be better option.
If after some time you'll add next 'big' portion of new models you can enable temporary auto DDL again and using local git just to copy new parts. Then revert to own revolution and paste new parts generated by Ebean plugin.
Biesior basically summed it up quite well. However, as a beginner in Play, I find that a bit more clarification with a concrete example might be helpful.
First, the following example is for Java.
Suppose you added a new field
public String dum_str;
in your model Dum. Then, you will need a 2.sql
under conf/evolutions/
like this:
# --- !Ups
ALTER TABLE dum ADD COLUMN dum_str VARCHAR(255);
# --- !Downs
ALTER TABLE dum DROP dum_str;
I hope this would be helpful.
Backup as a script the current db. Make your changes in the Java model. Let Play apply the changes and recreate the DB Then Restore your data.
Attn: Do not change existing fieldnames otherwise it won't work.
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