I am curious if there is a standard or open-source application that allows a small team of developers to share MySQL database update/modification scripts?
Right now all the developers have a VM with their own instance of a database, so there are no conflicts and each can have separate development environment. When one makes a DB change we add the SQL scripts to a SQL text file in SVN, which is then run by each dev in their own environment when necessary.
The issue that we are having is that when someone updates the file, the others run the script, and then we add additional changes. It gets very confusing and we get errors if there are ALTER table statements, etc.
We don't want to use DB replication because if one dev destroys their DB we don't want the others to be affected.
We use ExpressionEngine and I've noticed they use PHP to check/validate SQL updates, is that the direction we will need to go?
Anyone else deal with this issue? If so, what did you end up using?
A fairly simple solution is to have a directory, instead of a single file. Then each time a Dev makes a change, they add a "patch file" to the directory. Other developers can get their databases up to date by running any patches they haven't yet run.
This can even be automated by having a metadata table in the database to track which patches have been run and writing a script to run any that haven't.
Lorna Mitchell has blogged about some strategies to doing this:
http://www.lornajane.net/posts/2010/simple-database-patching-strategy
http://www.lornajane.net/posts/2012/taking-on-a-database-change-process
The comments are full or people recommending various tools to help with the process. Personally, I just have a fairly simple script and have no need for larger libraries, but your mileage may vary.
Perhaps what you want is migration support.
Then, you put the migration code in whatever CVS you use and each team member migrates (i.e. runs the migration script) on their box, and this syncs all databases.
The framework I use (yii) supports it but I'm pretty sure there are some standalone solutions if you don't want to have to bring the whole framework over.
I'm developing a website. I have a remote and local copy, and I develop on the local copy, and then when I've got a stable version I copy up all the PHP files and then I have to make the remote live MySQL database look like my local one.
I typically delete the remote, live database (as long as I'm not deleting new changes) and re-import it from a .sql file using PHPMyAdmin.
I want to set up a more reliable, correct, and idiot-proof, version updating system for my database. Is MySQL server replication the right answer? How is this usually done?
No, you never want a development/test environment replicating to a live database. If you accidentally dropped a table, you'd wipe out the live site.
Better to use something like http://www.mysqldiff.org/
Arguably the best way to do this is migrations. Migrations are essentially code which is stored with your application that update the database schema as it changes. The nice thing about migrations is that they can be versioned and it's easy to associate changes in the database schema with changes in the code. When used correctly, you can also use migrations to roll back the database to any previous state.
For an example, check out the use of migrations in the Yii framework.
I am looking for some advice on version control with our databases.
We currently have a few developers all running their own local development versions of website projects.
These websites are also available for the client to see on a staging server.
The issue I am having is that I may get the latest database from the stage server, then make changes to this on my local copy.
But in the meantime, the client has amended their CMS on the staging.
I was reading about SQL replication, is this a good idea? I was thinking that whenever a change is made on the staging site it will replicate to our local server and update that database.
Anyway, thoughts are appreciated.
If each developer gets a slave of the master (staging) and do local changes they will probably break replication as replicated statements will break if the slave schema isn't compatible. So all changes have to go on the staging server, and all developers would get them and if they haven't the latest source the source would break... So, while that might work I think it will be difficult.
I would suggest to do database changes in files that each environment have to run. There are a few you could investigate liquibase and dbdeploy
What we have done is to add a db_version table with one column, that after every change the version is incremented to reflect the date - 20101229, 20110305, 20110808, 201110808a, etc.
All the changes are stored in a single file SQL under the source control, and most the the changes are create table, alter table, insert (small static data), etc. Every time a developer want to change the schema it can know all the changes were made relative the the version he has, and update his schema
I've been reading this site here and there and appears as though you guys have a wonderful community.
As for my background, I am a sophomore at university familiar with SQL, C++, Visual Basic, and some PHP. One of my school projects for the summer term involves building a web application that allows users to log in and schedule specific timeslots over the internet. Typically, I have been the only person working on a project, but in this case I will be part of a group. Since we're all relatively new to working as a team, I would like to set up source control for my group so we're not all working off a shared drive somewhere. Additionally, I would like to make sure that all of us are able to test our changes in some sort of development server that hosts an instance of our website.
My actual question is in regards to the toolset that we should use to achieve this. As a group, we are most familiar with PHP and MySQL so we'll end up using that for the code and database. I have used SVN in the past for my own personal use, but my group members aren't very familiar with source control. We'll probably stick with something simple like Excel for the project management and bug tracking side of things. Ideally, we would like the tools to be free and open source.
How as a group should we manage the construction of the actual application? Are there methods out there that I can use that will allow any one of us to move the files to our development machine and keep track of who did it so we don't end up overwriting each other's changes? If this is not possible, one of us will write some scripts to handle it - but I would like to avoid building basically a separate software application that will only be used to manage our project. Another issue I foresee will be updating the database running on the development machine. Are there any standardised methods that we can use to manage our SQL scripts among the four of us?
I do not expect a really long winded answer here (after all, this is our project!), but any helpful tips would be greatly appreciated. Once I return from holiday I am looking forward to getting started! Thanks!
I recommend your group use source control to synchronize your code. You can either setup your own server or just use a free provider such as github, Google code, or bitbucket.
If you do decide to use one of these sites, a nice feature is that they provide free issue tracking as well, so you can use that instead of Excel.
The best way to manage the SQL scripts is to break them out into separate files and place them under source control as well. You can either create .sql files, or use a tool to manage these changes - for example, have a look at Ruby on Rails' Migrations. This may take some effort to setup, but you'll thank yourself later if you are working on a project of any size...
Draw up a plan for how you would do it if it were just you.
Split the plan up into tasks that take around 3-4 hours to complete. Make sure each task has a measurable objective.
Divy out the tasks. Try to sort them if possible to maximize developer efficiency.
Teach them to use source control. Explain to them that they will use this (maybe not svn, but SOMETHING) in a few years, so they might as well learn how now. Additionally, this will help in every group project they do down the road.
Make a script for building and running your tests. Also script your deployment. This will ensure you have the same mechanism going to live as you do going to test, which increases the number of defects found in testing. (This is as opposed to letting them exist but not found in testing.)
You mentioned updating the development database. It would be entirely reasonable to dump the development database often with a refresh from live. You may want to make 3 environments. Development, staging, and production. The development database would contain fabricated test data. The staging database would have a copy of live (recent to within a few days maybe.) And of course live is live.
Excel works fine as a "bug database." Consider putting it in source control that you manipulate and commit. This will give you a good idea of what happened over time, and you can correct mistakes quicker.
As far as source/version control, I would recommend subversion. There are some GUI tools they might use, or even webDAV to access the SVN. This will allow users to edit files collaboratively and also give you details as to who edited what, when, and why... SVN will also do a pretty good job at merging files that happen to be saved at the same time.
It's not the easiest concept to wrap your head around, but its not very complicated once you get running.
I suggest having everyone read the first chapter from: http://svnbook.red-bean.com/en/1.5/
and they should have a good idea of what's happening.
I am also curious to see what people have to say about the database
How as a group should we manage the construction of the actual application? Are there methods out there that I can use that will allow any one of us to move the files to our development machine and keep track of who did it so we don't end up overwriting each other's changes?
It sounds like you're looking for build management. In the case of PHP, a true "build" is as simple as a collection of source files because the language is interpreted; there is no compilation.
It just so happens that I am one of the developers for BuildMaster, a tool which basically solves every problem you have listed in your question... and it also sounds like it would be free in your case under the Community Edition license. I'll try to address some of your individual pain points and how BuildMaster could be used as a solution.
Source Control
As suggested by others, you must use it. The trick when it comes to deployment is to set up some form of continuous integration so that every time someone checks in, a new "build" is created. In BuildMaster, you can set this up for any source control provider you want.
Issue/Bug Tracking
Excel will work, but it's not an optimal solution. There are plenty of free issue tracking tools you can use to manage your bugs and features. With BuildMaster, you can link your bugs and features list with the application by their release number so you could view them within the tool at any time. It can also modify issue statuses and add descriptions automatically if you want.
Deployments
Using BuildMaster, you can create automated deployment plans for your development environment, e.g.:
Get Latest Source Code
Create Artifact
Copy Files To Development Machine
Deploy Configuration Files
Update Database
The best part is, once you set these up for other environments (glowcoder's point #6), pushing all of your code and database updates is as simple as clicking a button.
Another issue I foresee will be updating the database running on the development machine. Are there any standardised methods that we can use to manage our SQL scripts among the four of us?
Database Updates
Not surprisingly, BuildMaster handles these as well by using the change scripts module. When a member of your team creates a script (e.g. ALTER TABLE ADD [Blah] INT NOT NULL) he can upload it into BuildMaster, then run it on any environment you have created.
The best part is that you can add a step in your automated deployment and never worry about it again. As Justin mentions, you can use .sql files for your object code (stored procedures, views, triggers, etc.) and have those executed on every build since they are essentially code anyway. You can keep those in source control.
Configuration Files
One aspect of all this you may have neglected (but will inevitably run into) is dealing with configuration files. With PHP, you may have an .htaccess file, a php.ini file, a prepend.php, or roll your own custom config file. Since by definition configuration files need to change between your personal machine and the development machine, grabbing them from source control wouldn't necessary work without some bit of hacking a la:
if (DEV) {
// do one thing
}
else if (PROD) {
// do another
}
With BuildMaster, you can templatize your configuration files and associate them with an environment so they can be deployed automatically. It will also maintain a history of changes for you.
Automated Testing
If you want the full ALM effect, you can automatically unit test your code during an automated build, and notify you if anything fails so you know as soon as possible that something is broken.
Apologies for the "long winded" response, but I feel like you're already ahead of the game by observing the problems you might run into in the future and really believe BuildMaster will make all of this deployment stuff simple for your team so you can focus on the fun part, coding!
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What are the best methods for tracking and/or automating DB schema changes? Our team uses Subversion for version control and we've been able to automate some of our tasks this way (pushing builds up to a staging server, deploying tested code to a production server) but we're still doing database updates manually. I would like to find or create a solution that allows us to work efficiently across servers with different environments while continuing to use Subversion as a backend through which code and DB updates are pushed around to various servers.
Many popular software packages include auto-update scripts which detect DB version and apply the necessary changes. Is this the best way to do this even on a larger scale (across multiple projects and sometimes multiple environments and languages)? If so, is there any existing code out there that simplifies the process or is it best just to roll our own solution? Has anyone implemented something similar before and integrated it into Subversion post-commit hooks, or is this a bad idea?
While a solution that supports multiple platforms would be preferable, we definitely need to support the Linux/Apache/MySQL/PHP stack as the majority of our work is on that platform.
In the Rails world, there's the concept of migrations, scripts in which changes to the database are made in Ruby rather than a database-specific flavour of SQL. Your Ruby migration code ends up being converted into the DDL specific to your current database; this makes switching database platforms very easy.
For every change you make to the database, you write a new migration. Migrations typically have two methods: an "up" method in which the changes are applied and a "down" method in which the changes are undone. A single command brings the database up to date, and can also be used to bring the database to a specific version of the schema. In Rails, migrations are kept in their own directory in the project directory and get checked into version control just like any other project code.
This Oracle guide to Rails migrations covers migrations quite well.
Developers using other languages have looked at migrations and have implemented their own language-specific versions. I know of Ruckusing, a PHP migrations system that is modelled after Rails' migrations; it might be what you're looking for.
We use something similar to bcwoord to keep our database schemata synchronized across 5 different installations (production, staging and a few development installations), and backed up in version control, and it works pretty well. I'll elaborate a bit:
To synchronize the database structure, we have a single script, update.php, and a number of files numbered 1.sql, 2.sql, 3.sql, etc. The script uses one extra table to store the current version number of the database. The N.sql files are crafted by hand, to go from version (N-1) to version N of the database.
They can be used to add tables, add columns, migrate data from an old to a new column format then drop the column, insert "master" data rows such as user types, etc. Basically, it can do anything, and with proper data migration scripts you'll never lose data.
The update script works like this:
Connect to the database.
Make a backup of the current database (because stuff will go wrong) [mysqldump].
Create bookkeeping table (called _meta) if it doesn't exist.
Read current VERSION from _meta table. Assume 0 if not found.
For all .sql files numbered higher than VERSION, execute them in order
If one of the files produced an error: roll back to the backup
Otherwise, update the version in the bookkeeping table to the highest .sql file executed.
Everything goes into source control, and every installation has a script to update to the latest version with a single script execution (calling update.php with the proper database password etc.). We SVN update staging and production environments via a script that automatically calls the database update script, so a code update comes with the necessary database updates.
We can also use the same script to recreate the entire database from scratch; we just drop and recreate the database, then run the script which will completely repopulate the database. We can also use the script to populate an empty database for automated testing.
It took only a few hours to set up this system, it's conceptually simple and everyone gets the version numbering scheme, and it has been invaluable in having the ability to move forward and evolving the database design, without having to communicate or manually execute the modifications on all databases.
Beware when pasting queries from phpMyAdmin though! Those generated queries usually include the database name, which you definitely don't want since it will break your scripts! Something like CREATE TABLE mydb.newtable(...) will fail if the database on the system is not called mydb. We created a pre-comment SVN hook that will disallow .sql files containing the mydb string, which is a sure sign that someone copy/pasted from phpMyAdmin without proper checking.
My team scripts out all database changes, and commits those scripts to SVN, along with each release of the application. This allows for incremental changes of the database, without losing any data.
To go from one release to the next, you just need to run the set of change scripts, and your database is up-to-date, and you've still got all your data. It may not be the easiest method, but it definitely is effective.
The issue here is really making it easy for developers to script their own local changes into source control to share with the team. I've faced this problem for many years, and was inspired by the functionality of Visual Studio for Database professionals. If you want an open-source tool with the same features, try this: http://dbsourcetools.codeplex.com/
Have fun,
- Nathan.
If you are still looking for solutions : we are proposing a tool called neXtep designer. It is a database development environment with which you can put your whole database under version control. You work on a version controlled repository where every change can be tracked.
When you need to release an update, you can commit your components and the product will automatically generate the SQL upgrade script from the previous version. Of course, you can generate this SQL from any 2 versions.
Then you have many options : you can take those scripts and put them in your SVN with your app code so that it'll be deployed by your existing mechanism. Another option is to use the delivery mechanism of neXtep : scripts are exported in something called a "delivery package" (SQL scripts + XML descriptor), and an installer can understand this package and deploy it to a target server while ensuring structural consistency, dependency check, registering installed version, etc.
The product is GPL and is based on Eclipse so it runs on Linux, Mac and windows. It also support Oracle, MySQL and PostgreSQL at the moment (DB2 support is on the way). Have a look at the wiki where you will find more detailed information :
http://www.nextep-softwares.com/wiki
Scott Ambler produces a great series of articles (and co-authored a book) on database refactoring, with the idea that you should essentially apply TDD principles and practices to maintaining your schema. You set up a series of structure and seed data unit tests for the database. Then, before you change anything, you modify/write tests to reflect that change.
We have been doing this for a while now and it seems to work. We wrote code to generate basic column name and datatype checks in a unit testing suite. We can rerun those tests anytime to verify that the database in the SVN checkout matches the live db the application is actually running.
As it turns out, developers also sometimes tweak their sandbox database and neglect to update the schema file in SVN. The code then depends on a db change that hasn't been checked in. That sort of bug can be maddeningly hard to pin down, but the test suite will pick it up right away. This is particularly nice if you have it built into a larger Continuous Integration plan.
Dump your schema into a file and add it to source control. Then a simple diff will show you what changed.
K. Scott Allen has a decent article or two on schema versioning, which uses the incremental update scripts/migrations concept referenced in other answers here; see http://odetocode.com/Blogs/scott/archive/2008/01/31/11710.aspx.
If you are using C#, have a look at Subsonic, a very useful ORM tool, but is also generates sql script to recreated your scheme and\or data. These scripts can then be put into source control.
http://subsonicproject.com/
I've used the following database project structure in Visual Studio for several projects and it's worked pretty well:
Database
Change Scripts
0.PreDeploy.sql
1.SchemaChanges.sql
2.DataChanges.sql
3.Permissions.sql
Create Scripts
Sprocs
Functions
Views
Our build system then updates the database from one version to the next by executing the scripts in the following order:
1.PreDeploy.sql
2.SchemaChanges.sql
Contents of Create Scripts folder
2.DataChanges.sql
3.Permissions.sql
Each developer checks in their changes for a particular bug/feature by appending their code onto the end of each file. Once a major version is complete and branched in source control, the contents of the .sql files in the Change Scripts folder are deleted.
We use a very simple but yet effective solution.
For new installs, we have a metadata.sql file in the repository which holds all the DB schema, then in the build process we use this file to generate the database.
For updates, we add the updates in the software hardcoded. We keep it hardcoded because we don't like solving problems before it really IS a problem, and this kind of thing didn't prove to be a problem so far.
So in our software we have something like this:
RegisterUpgrade(1, 'ALTER TABLE XX ADD XY CHAR(1) NOT NULL;');
This code will check if the database is in version 1 (which is stored in a table created automatically), if it is outdated, then the command is executed.
To update the metadata.sql in the repository, we run this upgrades locally and then extract the full database metadata.
The only thing that happens every so often, is to forget commiting the metadata.sql, but this isn't a major problem because its easy to test on the build process and also the only thing that could happen is to make a new install with an outdated database and upgraded it on the first use.
Also we don't support downgrades, but it is by design, if something breaks on an update, we restored the previous version and fix the update before trying again.
It's kind of low tech, and there might be a better solution out there, but you could just store your schema in an SQL script which can be run to create the database. I think you can execute a command to generate this script, but I don't know the command unfortunately.
Then, commit the script into source control along with the code that works on it. When you need to change the schema along with the code, the script can be checked in along with the code that requires the changed schema. Then, diffs on the script will indicate diffs on schema changes.
With this script, you could integrate it with DBUnit or some kind of build script, so it seems it could fit in with your already automated processes.
I create folders named after the build versions and put upgrade and downgrade scripts in there. For example, you could have the following folders: 1.0.0, 1.0.1 and 1.0.2. Each one contains the script that allows you to upgrade or downgrade your database between versions.
Should a client or customer call you with a problem with version 1.0.1 and you are using 1.0.2, bringing the database back to his version will not be a problem.
In your database, create a table called "schema" where you put in the current version of the database. Then writing a program that can upgrade or downgrade your database for you is easy.
Just like Joey said, if you are in a Rails world, use Migrations. :)
For my current PHP project we use the idea of rails migrations and we have a migrations directory in which we keep files title "migration_XX.sql" where XX is the number of the migration. Currently these files are created by hand as updates are made, but their creation could be easily modified.
Then we have a script called "Migration_watcher" which, as we are in pre-alpha, currently runs on every page load and checks whether there is a new migration_XX.sql file where XX is larger than the current migration version. If so it runs all migration_XX.sql files up to the largest number against the database and voila! schema changes are automated.
If you require the ability to revert the system would require a lot of tweaking, but it's simple and has been working very well for our fairly small team thus far.
Toad for MySQL has a function called schema compare that allows you to synchronise 2 databases. It is the best tool I have used so far.
I like the way how Yii handles database migrations. A migration is basically a PHP script implementing CDbMigration. CDbMigration defines an up method that contains the migration logic. It is also possible to implement a down method to support reversal of the migration. Alternatively, safeUp or safeDown can be used to make sure that the migration is done in the context of a transaction.
Yii's command-line tool yiic contains support to create and execute migrations. Migrations can be applied or reversed, either one by one or in a batch. Creating a migration results in code for a PHP class implementing CDbMigration, uniquely named based on a timestamp and a migration name specified by the user. All migrations that have been previously applied to the database are stored in a migration table.
For more information see the Database Migration article from the manual.
Try db-deploy - mainly a Java tool but works with php as well.
http://dbdeploy.com/
http://davedevelopment.co.uk/2008/04/14/how-to-simple-database-migrations-with-phing-and-dbdeploy.html
I would recommend using Ant (cross platform) for the "scripting" side (since it can practically talk to any db out there via jdbc) and Subversion for the source repository.
Ant will allow you to "back up" your db to local files, before making changes.
backup existing db schema to file via Ant
version control to Subversion repository via Ant
send new sql statements to db via Ant
IMHO migrations do have a huge problem:
Upgrading from one version to another works fine, but doing a fresh install of a given version might take forever if you have hundreds of tables and a long history of changes (like we do).
Running the whole history of deltas since the baseline up to the current version (for hundreds of customers databases) might take a very long time.
There is a command-line mysql-diff tool that compares database schemas, where schema can be a live database or SQL script on disk. It is good for the most schema migration tasks.