rails 3:how to generate models for existing database tables - ruby

I've configured my database.yml to point to my existing mysql database
how can I generate models from it?
rails generate model existing_table_name
only gives an emty model..

You can try Rmre. It can create models for existing schema and it tries to create all relationships based on foreign keys information.

A Rails model doesn't show your fields, but you can still use them. Try the following. Assuming you have a Model named ModelName and a field called "name", fire up the Rails console and type:
ModelName.find_by_name('foo')
Given a name that exists in the DB, you should see results.
Rails doesn't infer relationships though, but if your database follows Rails conventions they are easily added.
Update
I've noticed this particular lack of explicitness ("magic") is a source of confusion for newbies to Rails. You can always look in schema.rb to see the models and all the fields in one place. Also, if you would prefer to see the schema for each model in the model file, you can use the annotate_models gem, which will put the db schema in a comment at the top of the model file.

Your answer is:
$ rake db:schema:dump
That will set a new db/schema.db to create a schema of your DB.

ActiveRecord doesn't parse a schema definition. It asks the DBM for the table defs and figures out the fields on the fly.
Having the schema is useful if you are going to modify the tables via migrations.
Schema Dumping and You will help you dump it to use as a reference for building migrations.
ActiveRecord makes some suppositions about the table naming and expects an id field to be the primary key with a sequential number as the type. Having the migrations would help you to refactor the tables and/or fieldnames and types, but you can do those same things via your DBM's command-line. You don't really have to follow ActiveRecord's style but doing so helps avoid odd errors and lets AR infer things to make your life easier.

Could try Magic Model Generator

Take a look at rare_map gem.
https://github.com/wnameless/rare_map
It works both on Rail 3 and 4.

Related

How to create Laravel model from migration?

I found many results how to create migration from a model, but is there any way to create a model from migrations?
Basically I want to give a table name, and if there is multiple migration files (one to create and others to update the previous states) the model could be updated.
Is there any solution for this?
I'm not sure that there's a good way to create a model directly from migrations, as it depends on what database you use as to the exact structure of your tables.
There seems to be a package which support generating the models from your database, however:
https://github.com/laracademy/generators

using laravel migrations to access tables already created

I have some tables that are already created in the database. The migrations seem to require that you first destroy the table and then create it. From what I understand, the creation process generates a "model" at the same time as well as "getters" and "setters" for the fields.
The problem is that I have a database full of tables already. I would like to access the tables that have already been created using Laravel as an interface. Is there a way to generate a model, getters and setters for tables that already exist?
How can I best do this?
TIA
The default model generator doesn't create any getters or setters. All it does is create a basic model class with the correct model name based on the table name. You can create the models without actually creating the migration. The command is php artisan make:model ModelName.
So the answer to your question is no, there isn't any. You need to manually create each model and add the methods yourself. You might try your luck with some laravel package which might do this for you.
Note : Laravel Eloquent is an ActiveRecord implementation. You don't need any getters or setters to work with the table columns. Even a completely empty model with the correct name to match the table would be enough to start using Eloquent.

Postgres ActiveRecord limit table size to one row

I am creating a custom CMS using Sinatra and Postgres with sinatra-activerecord enabled. I am creating a model called SiteInfo which will store information such as the about_description, about_photo, tagline, etc. Is there a way within the migration to create that SiteInfo table to specify that there can only be one row? There's no way through the interface for the admin or user to create an additional one, I'm just wondering.
To answer your question: No, you can't, and there is no need for.
You'll want to do something like SiteInfo.first to load your information anyway.

Generate Propel migration file for data entry alone

Is it possible to generate a Propel migration file without modifying the schema? I only need to insert values.
Thanks.
You can generate a blank migration like this:
propel migration:create
Yes. Just call the diff target in the Propel 1 command, which will create a migration class.
(Propel on MySQL for me always creates spurious differences e.g. between FLOAT and DECIMAL, which I delete manually. I don't know if it would refuse to create a class if no differences were found).
Propel migration system is not able to insert values, only update your database structure when you update your schema.
If you use Symfony2, you can use the command propel:fixture:* to insert data for test purpose.

Name conflicts in Entity Framework using database schemas?

I have these two tables in my database:
client.Employee
employee.Employee
When I try to import this into entity framework I get two table objects created:
Employee
Employee1
Is there a way to handle naming conflicts that will work better than this? And really, I would prefer that my schema is represented some how for non conflicting tables as well.
Unfortunately no. Information about schema is only included in storage description (SSDL) and it is not passed to conceptual model (CSDL) so in conceptual model you have two entities named Employee and EF is using the most basic way to resolve that. Another problem is that this probably cannot be modified because generating model from database is not driven by any T4 template which can be changed whereas reverse processing (generating SQL database creation script from model) is.

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