I have a 3 - 4000 nodes in a drupal 6 installation on mysql and want to access these data through my django application. I have used manage.py inspectdb to get a skeleton of a model structure. I guess that there are good/historical reasons for drupal's database schemes, but find that there are some hard to understand structure and that there are some challenges in applying django models on the database. Some experiences this far are:
node and node revision are intertwined and I solved this by using a OneToOneField (don't need the versions). This meens that the node's body gets accessible through node.vid.body, but it works.
Foreign keys need to define the proper db_column to sort out the primary keys.
Terms need to use an intermediary table with ManyToManyField.through.
Drupal stores both the original and the thumbnailed/resized versions of any image as files in the files table.
Does anyone have experiences in accessing drupal data in django?
Are there better solution to for example the node <-> node revision relationship?
Drupal stores time/dates as unix-style timestamps in integerfields. Any recommendations? How about time zones?
How will you make node and revisions to a OneToOne relation, when a node can have several revisions. It might be convenient/possible now, but can give you problems later.
You should make a Manager or method to access the the latest revision of the body instead.
The problem when dealing with timestamps, is always, that the timezone information is gone. If you want that info you will need to get it from the Drupal server. If you use the same timezone though, it shouldn't be a problem unless you need the times to be very specific.
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I have a database which is used by multiple projects. Each project has its database migration.
I have tried to google and read the knex documentation, but no luck. I have seen some suggestion to fake the migration files to trick the migration table, but I don't think it is a good solution.
I want to keep all the migrations data in one migration table. Is it possible on knex?
Having different set of migration files for each projects and trying to run them separately against the same migration table is not possible. There is no good solution for it and it would not make sense anyways to do it.
If migrations are not related to each other, then there is no reason to have them in the same table. On the other hand if they are related, then the files really should be hosted in the same place to guarantee that everything is done in correct order.
You can setup migration table name tableName (http://knexjs.org/#Migrations-API) to be different for every project in knex config.
However I would never recommend having multiple projects using the same database and everyone having separate migrations for it.
Only reason where that could be remotely acceptable would be the case where you don't have access to create separate databases for each project.
If projects are sharing the same data model (microservices with shared DB), in that case you should still be using multiple databases or to have single service which is the owner of the schema changes and the rest of the services should only read/write data.
I have a webapp which I am planning on converting into a REST api and have decided to use CakePHP for this - the current form is written in ColdFusion.
The database is a couple million records in size with 20 tables or so and a few associative tables that handle the many-to-many situations.
I'm looking for the best method to start the CakePHP solution mainly in regards to the database. Should I import my existing db and just use cake to access its current form? Should I bake a fresh database structure (in order to stay within the cake standards) then figure out how to get my data into the new db, and maintain relationships etc (how?)?
Edit:
There are many users on the existing app, but when the new CakePHP api is setup and ready to go, the old service will be closed to use the new one.
The current app is not designed in an MVC way, are you referring to Models as being synonymous with Tables? There are many existing tables with foreign key relationships but they are not named using the CakePHP standards - so not sure if this will break CakePHP or make its features not as usable.
Time is an issue, but I'd rather take the time now and get it done the correct way, instead of having to re-visit shortly.
I largely depends on your situation:
Are there people using the old application? - This will mean you
can't really create another database for your new app if you want to
access new information.
Is there really a need to change the relationships of models? - I don't think you should change unless you
really need to.
Cost - How much time are you willing to spend on the migration?
Note:
You can modify almost everything on your model to cope up with the previous database/table structure.
I'm working with a project which is using mysql as the database. The application is hosted with many clients and we are doing upgrades for the current live systems often.
There are some instances where the client has change the database structure(adding new tables) and causes some unexpected db crashes.
I need to log all the structural changes which were done at that database, so we can find the correct root cause for that. We can't do it 100% correct with diff tool because it will not show the intermediate changes.
I found http://www.liquibase.org/ tool but seems little bit complex.
Is there any well known technique or a tool to track database structural changes only.
well from mysql studio you can generate all object's schema definition and compare them with your standard schema definition and this way you can compare two database schema...
generate scrips of both database (One is client's Database and One is master copy database) and then compare it using file compare tool would be the best practice according to me because this way you can track which collumn was added, which column was deleted, which index was added like wise without any tool download.
Possiable duplication of Compare two MySQL databases ?
Hope this helps.
If you have an application for your clients to manage these schema changes, you can use a mechanism at application level. If you have a Python and Django-based solution, you could probably use South which provides schema change tracking and rollbacks.
I have an application written in PHP/MySQL (symfony, to be specific) that I'd (potentially) like to rewrite in Rails. I know how to create scaffolding for tables that don't exist yet, but how do I get Rails to read my existing table structure and create scaffolding based on that?
Update: it turns out I can run the following command to get Rails to generate models for me:
rails generate scaffold Bank --no-migration
But it doesn't give me forms. I would prefer something that gives me forms.
The answer is db:schema:dump.
http://guides.rubyonrails.org/migrations.html
The easiest route is to pretend that you are writing a fresh app with a similar database schema - you can then create your models and migrations with the old schema in mind, but without being restricted by it. At a later stage, you can create a database migration script to copy all the old data into the new schema.
I'm doing this right now. The benefit of this approach is that you can take advantage of all of the rapid development tools and techniques provided by Rails (including scaffolds) without being slowed by trying to retrofit to the exact same schema.
However, if you do decide that you don't like this approach, and you do need to map your new models to existing tables, there are a number of configuration options provided by active record where you can override the convention over configuration naming patterns and map model names to tables names, set oddly named ID fields etc. For example:
class Mammals < ActiveRecord::Base
set_table_name "tbl_Squirrels"
set_primary_key :squirrel_id
end
The above will help Rails attempt to read your existing table, but success will depend upon how well the existing table structures matches Rails conventions. You may have to supply more configuration information to get it to work, and even then it might not work.
Finally, it may be worth considering the use of DataMapper which I believe is more suited to existing brownfield databases than ActiveRecord, because it allows you to map everything, but of course you will need to learn that API if you don't already know it.
I'm in the process of setting up a new WordPress 3.0 multisite instance and would like to use Sphinx on the database server to power search for the primary website. Ideally, this primary site would offer the ability to search against its content (posts, pages, comments, member profiles, activity updates, etc.) as well as all of the other sites that are a part of the network. Because we'll be adding new sites to the network on a regular basis, I'd like to be able to dynamically add those newly generated tables to the Sphinx .conf file (instead of editing the file and reindexing every time we add a new site).
Unfortunately, MySQL doesn't seem to support wildcards when specifying the table(s) in a query string. The best solution I've come across for grabbing a dynamic set of tables is grepping but I'm pretty certain I don't know how to do this within the .conf file (unless it's possible through magical sorcery).
Is it possible to dynamically specify tables to add to the Sphinx index? Or is this going to cause such performance issues that I'm using the wrong tool?
You could try to dynamically modify the .conf file instead.
You could query from a MySQL view that aggregates the many tables. You'd have to recreate the view with each change to the list of blogs, but I believe that all the hooks exist to support that and it should be easy enough to construct the view query.
The bigger problem may be in trying to find a suitable unique record ID for the posts in Sphinx. It has to be a straight INT, but the post IDs from the different blogs will collide with each other.
I think you can create triggers (INSERT/UPDATE/DELETE) in MySQL on the interested tables (e.g. posts, comments etc) and migrate the data to centralized global tables that are indexed by Sphinx in real time.
The point is how you can create those triggers automatically? Either you can run a cron job to scan for new tables in MySQL, or I believe you can write a simple Wordpress plugin that hook when a blog is activated.