How to use Evolutions in Play Framework 2.0?

2019-03-21 05:14发布

For play 1.x, we can use play evolutions:apply, How can I do it in play-2.0-beta?

1条回答
你好瞎i
2楼-- · 2019-03-21 05:29

Evolution:apply is run automatically upon application start up. What is missing in Play 2.0-rc1 is a way to generate the evolutions scripts, and to manually apply them from the SBT console.

But here is how to create them manually.

Say you have the following definition in application.conf

db.mydb.driver=org.h2.Driver
db.mydb.url=jdbc:h2:mem:play

Play2 will look for evolution in the following folder: application/db/evolutions/mydb/ In this folder, evolutions shall be stored as sql file, using the evolution step as the file name.

For instance:

application/db/evolutions/mydb/1.sql
application/db/evolutions/mydb/2.sql
application/db/evolutions/mydb/3.sql

Now the sql itself has the following structure:

# --- !Ups
create table company (
  id                        bigint not null,
  name                      varchar(255),
  constraint pk_company primary key (id));
# --- !Downs
drop table if exists company;

!Ups are used to upgrade the model to the next evolutions
!Downs are used to revert the !Ups

Like I said in the intro, evolutions will be magically applied upon application startup.

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