When I perform flyway clean, it removes everything from my public database including all tables, but also all routines.
The problem is that when I perform my first migration, i'm using Postgres's routine gen_uuid. Consequently, the migration fails and i'm stuck in a loop.
Is that normal ?
I found the answer, turns out there were a strong coupling between migrations written by the previous team on 2 pg extensions, pgcrypto and unaccent that was NOT written as migrations by us but by another container in the stack.
The solution is to let Flyway manage the creation of these extensions.
Related
In testing an upgrade to our Postgres database, we've discovered that one of our oldest versioned migration files is no longer valid SQL. This isn't an issue for the production database which (of course) has those migrations already in the schema_history_table, but standing up any new sandboxes is now made impossible by this broken V file.
What's the best way to bring an old V file into the modern world without forever orphaning our production database?
Of the top of my head I can think of a few possible options.
Configure postgres to enable previous version compatibility. I'm no expert at this, but I think there are some options here.
Just modify the historic migration scripts to they now work with the new version. This will mean that you can't stand up old versions any longer, but does this matter to you? I think that you'll need to run flyway repair after you do this, as Flyway will detect that the files have been tampered with.
Create a parallel set of scripts, one for each version, putting them in different folders. Then use the flyway.locations option to specify different folders depending on the version of the target.
I'm currently using Flyway to manage migrations on an application which uses Postgis (PostgreSQL geospatial extension).
This plugin uses a table called spatial_ref_sys which is located in the same schema the application uses too, when I call mvn flyway:clean I'm getting an error indicating that Flyway was unable to delete this table (it was created using user postgres); if I change the owner to my application database user, then the error changes to:
ERROR: cannot drop table spatial_ref_sys because extension postgis requires it
[ERROR] Hint: You can drop extension postgis instead.
However, I don't want to drop these items, which are external to my application logic, as they are just "auxiliars".
I have seen two questions where Axel Fontaine said the feature of ignore some table(s) is not supported (both questions are two or more years old), I even have cloned the GitHub repo to add this feature to Flyway by myself, and I've been reading some parts of the code where this change could be implemented; but I'm suspecting it will affect several parts of the code, and my unknowledgement about it could make the things harder..
So, I'm looking some help to implement the change, or maybe some ideas to do a work-around this issue..
I'm thinking in simply do DROP of the entire database and recreate it, then recreate the geospatial extensions (Postgis, PGRouting, etc), and make the migration using Flyway, but this will be not much suitable if I have to do it several times during the development process..
I had this problem for test environment and i wanted to delete schema by flyway. I fixed it by manipulating flyway spring bean sequence. First, I dropped postgis extension before flyway.clean() and then at the first line of V1__init.sql add CREATE EXTENSION postgis SCHEMA public;:
#Bean
#Profile("test")
public Flyway flyway(DataSource dataSource) {
Flyway flyway = new Flyway();
flyway.setDataSource(dataSource);
flyway.setLocations("classpath:db/migration");
runSql("drop extension IF EXISTS postgis CASCADE;", dataSource);
flyway.clean();
flyway.migrate();
return flyway;
}
I just made a migration file.sql to add a new table to the database, and I ran the flywayMigrate command sbt flywayMigrate. Now I realised I missed adding two columns to the same table. I have an option to write another migration, but I don't want to increase the number of migrations when I can rollback and change the migration I just made to create a table and add two more columns to it. Can you tell me how do I rollback some number of migrations and change them, and run sbt flywayMigrate again?
You don't necessarily have to re-run whole migration. There's a table which flyway uses for metadata and I think it is called schema_version. You can set the last applied migration id (there are some hashes to be set IIRC, but you will be able to figure them from error messages, if they don't match) and flyway would pick up from there.
As described in Flyway FAQ rollback scripts are not supported.
You have options to:
restore your database from backup
drop and recreate the database rerunning all the migration scripts
manually rollback the migration and remove its record from metadata table
There's a lot of articles on this topic and I've spent hours reading them today. It's so confusing - most of the articles seem to try to save existing databases and even migration history.
My databases were created initially by code first migrations. I really don't have any data that's important to keep. So I would like to just delete my databases and the .cs migration history files in /Migrations folder. Then run add migrations and update-database to recreate the databases.
From what I'm reading, this is not the way to do it? My confusion is partially due to the totally different procedures suggested and the extensive coding for many solutions.
Can I delete my databases and /Migrations/*.* (except for Configurations.cs) and essentially reinitialize Migrations?
Btw, I am using VS Web Express 2013, MVC5/C#, SQL Express 2012.
I regularly do this during the development phase of my projects, as long as you are happy to lose your data then it is fine to delete the database, and migration classes, the database will be recreated when you run update-database.
During early development phases, my approach is to utilise automatic migrations and just use update-database which means nothing is created in the migrations folder, so you don't have to manage the extra files.
Obviously this approach isn't good once you start deploying the database for real, where I personally wouldn't use automatic migrations.
To enable automatic migrations, run the Enable-Migrations –EnableAutomaticMigrations command in the Package Manager Console.
More reading:
http://msdn.microsoft.com/en-us/data/dn481501.aspx
http://msdn.microsoft.com/en-gb/data/jj554735.aspx
Before anyone marks this as a duplicate, none of the questions similar to this addressed any of my concerns or answered any of my questions.
I am currently developing all the POCOs and data contexts in a library project, and running migrations from within this project. The database I'm updating is the development database.
What do I do if I want to create the current schema to a fresh, new database? I figure that all I have to do is to change the connection string in web.config and run Update-Database, correct?
While the live/production database is up and running, I want to add new columns and new tables to the schema, and test it out in development. So I switch back the connection string to the development database's connection string, and run Update-Database.
Going back and forth between two databases seems like I'll get conflicts between _MigrationHistory tables and the auto-generated migration scripts.
Is it safe to manually delete the _MigrationHistory tables in both databases, and/or delete the migration files in /Migrations (so I'll run Add-Migration again)? How do we manage this?
What do I do if I want to create the current schema to a fresh, new database?
- Yes, to create fresh database to the current migration level you simply modify the connection string to point to a database that does not yet exist and run update-database. It will run all the migrations in order.
As far as migrating to the Production database, I am running the update-database command with the -script switch to acquire the raw sql and then applying that script to the production database manually. This is helpful if you need to keep a record of sql commands run against the database as well. Additionally, you can generate the script explicitly from a specific migration to another specific migration via some of the other update-database switches.
Alternatively, you can create an Idempotent script that works from any migration by using the–SourceMigration $InitialDatabase switch and optionally specify an end migration with –TargetMigration
If you delete the _MigrationHistory tables you will have issues where the generated script will be trying to add columns that already exist and such.
You may find the following link helpful:
Microsoft Entity Framework Migrations
I would suggest having a separate trunk in your source code repository - one pointing to production and one to development to avoid risks of switching between the two in visual studio.
Me also had the same problem, even when using one and the same database - due to some merges in the repository, and the mix of automatic/manual migrations. For some reason the EF was not taking into account the target database, and calculating what scripts need to me executed, based on what is already in the database.
To fix this, I go to the [__MigrationHistory] table on the target database and get the latest migration name. This will help EF to determinate the state of the DB, and will execute just the scripts needed.
then the following script is run:
update-database -script -sourcemigration {latest migration name}
This creates update script that is specific to the target database (the connection string should be correct, as discussed in the other comments)
you can also use -force parameter if needed
this way you can update any database to latest version, no mater in what version you found it, if it has MigrationHistory table.
Hope this helps
My production and my developmental database went out of synch and it gave me endless problems. I solved it using a tool from Red-Gate to match up the databases. After using the tool, the databases were exactly the same but my migration was not working and I started to get odd errors i.e. trying to add tables/ columns that already existed etc. I solved that. I just deleted the migration folder on the local, recreated it, added the initial migration, updated the database and then matched the data of this migration file (local) to the one on the host (delete all the data in the migration file on the host, and add the same data that is on the local into the host). A more detailed explanation is at:
migration synch developmental and production databases