Grails Data Migration Rollback

Question

Hi I'm trying something very simple with Grails domain class. I am adding to my class a field and I want to use data migration plugin to rollback once so that the field I added gets removed.

First I created the initial change log as followed:

grails dbm-generate-changelog changelog.groovy

Then I added the following to the Config.groovy file:

grails.plugin.databasemigration.updateOnStart = true grails.plugin.databasemigration.updateOnStartFileNames = ['changelog.groovy']

Then I added an extra field to my domain class and performed the following:

grails dbm-gorm-diff added-new-field.groovy --add

I ran the app (grails run-app), after which I perform a:

grails dbm-rollback-count 1

After which I run the app again using: grails run-app but the field is still there.

I am using MySQL for db. Here's how I have it configured in DataSource.groovy:

dataSource {
    pooled = true
    driverClassName = "com.mysql.jdbc.Driver"
dialect = "org.hibernate.dialect.MySQL5InnoDBDialect"
}
hibernate {
    cache.use_second_level_cache = true
    cache.use_query_cache = false
    cache.region.factory_class = 'net.sf.ehcache.hibernate.EhCacheRegionFactory'
}
// environment specific settings
environments {
    development {
        dataSource {
        dbCreate = 'update'
            url = "jdbc:mysql://localhost/dashboard?useUnicode=yes&characterEncoding=UTF-8"
    username ="foo"
    password = "bar"
    }
}

..... and on.....

Can someone guide me to how the rollback is performed? I am using: Grails 2.2.2 database-migration:1.3.2

"After which I run the app again using: grails run-app but the field is still there." The field in the domain class or the column in the table? — James Kleeh
I meant that field should not be there any longer since I'm rolling back to when the schema didn't have that field. — codeBarer

codeBarer codeBarer · Accepted Answer · 2013-06-17T19:44:45

When grails dbm-rollback-count 1 is performed It makes changes only to the database using the groovy changelog filed by taking the very last change set in the log and undoing that. If you run your app again the following lines in Groovy.config will put those fields back into the tables:

grails.plugin.databasemigration.updateOnStart = true grails.plugin.databasemigration.updateOnStartFileNames = ['changelog.groovy']

I'm not really sure what purpose dbm-rollback-count servers in my case but that it what it did. I was thinking that performing a rollback will not only remove the last changeset (added field) in the database but also remove that field variable from the domain class as well.

Grails Data Migration Rollback

1 Answers