Is there an easy way to do a "git rebase"-like operation for Grails Database Migration plugin changelog scripts?
I have already several changelog scripts on top of the initial changelog from an old domain model. Now I'm deploying the application to a new environment and there's no need to migrate the database contents.
I could delete the scripts and generate a fresh initial script from the current domain model but then I'd have to install Grails to the old environment and execute dbm-clear-checksums there, right?
Is there an easier way to tell dbm that I don't want to create an old domain and patch it to current level?
Run the dbm-changelog-sync script - it marks everything as having been run.
Related
I am looking for a solution to sync DB between multiple developers (us at the office..).
We use Wordpress and MAMP (for now, MAMP/Headless WP and NPM/React in the future) and we want to use Appveyor (or similar) to deploy at dev-server and live-server, and want the DB to be synced everywhere or at least among us and the dev server and have a secondary (free standing) on the live-server.
Can this be done with Liquidbase or is there a better option?
Thanks :)
I don't know a whole lot about WordPress and how it uses the database, but in theory this should be possible as long as you are talking about syncing the schema changes. If you are also trying to sync the data, then Liquibase is not the right tool for the job.
To do this with Liquibase, try installing using the installer and working through some of the examples to get an idea for how the tool works. The examples use a local h2 in-memory database, so it is pretty painless to try things and start over if you mess things up.
After getting a feel for things, you will want to use the Liquibase generateChangeLog command to create the initial changelog that contains all the instructions for creating the schema as it exists on the database you are using when you run generateChangeLog. Then test that you can run liquibase update on a separate database and have WordPress use that database successfully.
Once you have proven that workflow, you can continue by following this pattern:
Before making changes to the WordPress schema, run liquibase snapshot to create a JSON formatted snapshot of the "DEV" schema - the schema you are changing in development mode. You will need additional options to generate the JSON format snapshot.
Make the desired changes to the WordPress "DEV" schema, most likely by using the WordPress app itself.
Use liquibase diffChangeLog to compare the JSON snapshot to the newly-altered "DEV" schema. This will add changesets to the existing changelog file that describe how to alter the schema to create the desired changes.
Use liquibase changeLogsSync on the "DEV" schema to update the liquibase tracking tables so that liquibase knows that the changes in the changelog already exist in that database.
Use liquibase update against the "PROD" database to have the new schema changes show up in that environment.
This workflow is described in the Liquibase docs for the snapshot command.
ps - there is no d in Liquibase :-)
We have an JavaEE web application running with Maven to do the build process, JSF 2.2, Tomcat 7 as our server and MySQL 5.5 as our database. With the development of new features, sometimes we need to change our database structure. At this moment we have the work to do all this manually:
Wait until we have no clients online (around midnight)
Go to Tomcat manager
Undeploy context
Deploy new context
Go to phpMyAdmin and execute the SQL scripts
While our application is still "small" is still viable to do this process, but we are looking forward to automatize this. We already know about Jenkins, that can read our Git, build the .war using Maven and - not sure yet - do the deploy at Tomcat.
But I am not sure about how we will automatize our SQL scripts to execute when we deploy a new version. It needs to be robust, so it doesn't mess with our database, by for example, running it twice or something like that.
My question is if there is a better deployment process focusing on database changes that can help me.
Just to append the previous answer about liquibase, you could use the flywaydb too.
There are solutions for this out there. One of them is called Liquibase.
You can use liquibase to apply incremental database changes along with jenkins to automate build process.
I have the following scenario for my application:
1 Production Server
1 Test Server
n Development Computers
For database migration we use Hibernate Schema Update for the Schema and DBUnit for filling in alle the production data (on all servers/computers). When the schema update is done I generate a new DTD File for the new schema, so I can do a fresh import of the DBUnit XML. The application updates the database at startup with the XML file (only on development and test servers/computers!)
Of course this approach is not optimal and fragile. So I looked at Liquibase and Flyway. Both seem to be great tools, but what I do not get is: How do I migrate the data? In my case, I dump the data of the production system once a week and add it to the applications source control as a DBUnit XML file, so all developers have "fresh" data and the test server has current production data, too.
The problem I see with Liquibase and Flyway is, that there is no solution how to do automated diffs from the database data and generate the migration changes automatically.
So my idea is the following with the following steps:
Set Hibernate to validate instead of update.
When a STRUCTURAL database change is needed, I add it to the migration script for the major version
No database inserts are in the migration script.
Generate a new DTD for DBunit based on the new database structure
Generate the DBUnit XML from the production database.
Another idea would be to utilize flyways JavaMigration and provide an initial Database Dump based on DBUnit. All other changes for database data will be handled in migration scripts. But still there is the problem: How to make diffs from the current migration script state and the production database state?
It would be awesome if anyone could provide me hints how to handle my scenario :)
If your goal is to use dumps of the PROD database in DEV and TEST environments, I would:
Configure the DB migration tool to run on application startup (both Flyway and Liquibase support this through their respective APIs)
Package all the DB structure migrations together with the app
Dump both data and structure from PROD
This way, when the PROD database is restored to DEV or TEST, the old metadata table of the migration tool is restored as well.
When the app starts, the migration tool will discover that the db structure is outdated and upgrade it to the newest version. Done.
No need to use DBUnit for this.
The short answer is that all your changes would be done through Liquibase or Flyway.
We use Flyway, with the same prod/test/development setup.
We make all db changes (structure or metadata) using Flyway migration scripts, stored in source control. Each time we do a new deployment to an environment, we first run the migration scripts there (using either the command line tool or the maven plugin). The code first goes to development environment, gets integration tested there and keeps going to test and production.
The main thing to watch out for is that Flyway requires a linear versioning to the files, so if two developers check in migrations at the same time, one of them will have to rename theirs.
We have a great process for upgrading our clients' websites as far as updating html/js code and assets is concerned (by using Subversion) that we are very happy with.
However, when it comes to upgrading databases, we are without any formal process.
If we add new tables/fields to our development database, when it comes to rolling it out to the production server we have to remember our changes and replicate them. We cannot simply copy the development database on top of the production database as client data would be lost (e.g. blog posts, account info etc).
We are also now in the process of building a web-app which is going to come across the same issues.
Does anyone have a solution that makes this process easier and less prone to error? How do big web-apps get round the problem?
Thanks.
I think that adding controls to the development process is paramount. At one of my past jobs, we had to script out all database changes. These scripts were then passed to the DBA with instructions on what environment to deploy them in. At the end of the day, you can implement technical solutions, but if the project is properly documented (IF!!!) then when it comes time for deployment, the developers should remember to migrate scripts, along with code files. My $.02
In my opinion your code should always be able to create your database from scratch, therefore it should also handle upgrades too. It should check a field in the database to see what version the schema is at and handle the upgrades to the latest version.
I had some good luck with: http://anantgarg.com/2009/04/22/bulletproof-subversion-web-workflow/
The author has a database versioning workflow (with PHP script), which is decent.
Some frameworks have tools which deal with the database upgrade. For example rails migrations are pretty nice.
If no convenient tool is available for your platform you could try scripting modifications to your development database.
In my company we use this model for some of our largest projects:
If the X is the just deployed version of our application and it's not different then the latest development version.
We create a new directory for the scripts naming it for example - version x + 1 and add it to the subversion repository.
When developer wants to make modification to the development database, he creates the .sql script with a name "1 - does something.sql" that makes the modifications (they must be indestructible), saves it and then runs it on the development database. He commits the web app code and the sql scripts. Each developer does the same and maintains the order of the execution of scripts.
When we need to deploy the version X+1 - we copy the x+1 web app code and the scripts to the production server, we backup the database, run the sql scripts one by one on the production database and deploy the new web application code.
After that we open a new (x + 2) sql script directory and repeat the proces ...
We basically have a similar approach as Senad, we maintain a changes.sql file in our repo that developers put their changes in. When we deploy to production, we:
Run a test deployment to the QA server:
first reproduce the production environment (app & db) in the QA server
run changes.sql against the qa db
deploy the app to qa
run integration tests.
When we are sure the app runs fine in qa with the scripted changes to the db (ie. nobody forgot to include their db changes in the changes.sql, or references, etc.) we:
backup the production database
run the scripts in the changes.sql file against the production db
deploy the app
clear the changes.sql file
All the deployment is run through automated scripts so we now we can reproduce it.
Hope this help
We have folder migrations/ inside almost every project and tehere are so called, "up" and "down" scripts (sql). Every developer is obliged to write his own up/down script and to verify it against testing environment.
There are other tools and frameworks for migrations, but we haven't got the time to test it...
Some are: DoctrineDB, rails migrations, propel (I think...), capistrano can do it also..
Imagine you are developing a Java EE app using Hibernate and JBoss. You have a running server that has some important data on it. You release the next version of the app once in a while (1-2 weeks) and they have a bunch of changes in the persistence layer:
New entities
Removed entities
Attribute type changes
Attribute name changes
Relationship changes
How do you effectively set up a system that updates the database schema and preserves the data? As far as I know (I may be mistaking), Hibernate doesn't perform alter column, drop/alter constraint.
Thank you,
Artem B.
LiquiBase is your best bet. It has a hibernate integration mode that uses Hibernate's hbm2ddl to compare your database and your hibernate mapping, but rather than updating the database automatically, it outputs a liquibase changelog file which can be inspected before actually running.
While more convenient, any tool that does a comparison of your database and your hibernate mappings is going to make mistakes. See http://www.liquibase.org/2007/06/the-problem-with-database-diffs.html for examples. With liquibase you build up a list of database changes as you develop in a format that can survive code with branches and merges.
I personally keep track of all changes in a migration SQL script.
You can use https://github.com/Devskiller/jpa2ddl tool which provides Maven and Gradle plugin and is capable of generating automated schema migrations for Flyway based on JPA entities. It also includes all properties, dialects, user-types, naming strategies, etc.
For one app I use SchemaUpdate, which is built in to Hibernate, straight from a bootstrap class so the schema is checked every time the app starts up. That takes care of adding new columns or tables which is mostly what happens to a mature app. To handle special cases, like dropping columns, the bootstrap just manually runs the ddl in a try/catch so if it's already been dropped once, it just silently throws an error. I'm not sure I'd do this with mission critical data in a production app, but in several years and hundreds of deployments, I've never had a problem with it.
As a further response of what Nathan Voxland said about LiquiBase, here's an example to execute the migration under Windows for a mySql database:
Put the the mysql connector under lib folder in liquibase distribution for example.
Create a file properties liquibase.properties in the root of the liquibase distribution and insert this recurrent lines :
driver: com.mysql.jdbc.Driver
classpath: lib\\mysql-connector-java-5.1.30.jar
url: jdbc:mysql://localhost:3306/OLDdatabase
username: root
password: pwd
Generate or retrieve an updated database under another name for example NEWdatabase.
Now you will exctract differences in a file Migration.xml with the following command line :
liquibase diffChangeLog --referenceUrl="jdbc:mysql://localhost:3306/NEWdatabase"
--referenceUsername=root --referencePassword=pwd > C:\Users\ME\Desktop\Migration.xml
Finally execute the update by using the just generated Migration.xml file :
java -jar liquibase.jar --changeLogFile="C:\Users\ME\Desktop\Migration.xml" update
NB: All this command lines should be executed from the liquibase home directory where liquibase.bat/.sh and liquibase.jar are present.
I use the hbm2ddl ant task to generate my ddl. There is an option that will perform alter tables/columns in your database.
Please see the "update" attribute of the hbm2ddl ant task:
http://www.hibernate.org/hib_docs/tools/reference/en/html/ant.html#d0e1137
update(default: false): Try and create
an update script representing the
"delta" between what is in the
database and what the mappings
specify. Ignores create/update
attributes. (Do not use against
production databases, no guarantees at
all that the proper delta can be
generated nor that the underlying
database can actually execute the
needed operations)
You can also use DBMigrate. It's similar to Liquibase :
Similar to 'rake migrate' for Ruby on
Rails this library lets you manage
database upgrades for your Java
applications.