rare_map >= 2.0.0

Relational db to ActiveREcord models MAPper

RareMap can be used for BOTH standalone application & Rails

Installation:
```
gem install rare_map
```

Basic RareMap use

Standalone:

Create a new rare_map.yml with following lines in the root of your application

Rails:

Create a new config/rare_map.yml with following lines in rails

rare_map.yml

legacy:
  adapter: sqlite3
  database: db/db1.sqlite3

old_db:
  adapter: mysql2
  host: localhost
  database: db_name
  port: 3306
  username: user
  password: pw

Run following command in the root of your application or rails
```
$ raremap
```
Standalone: A demo.rb example is generated for you in the root of your application
RareMap console which is like rails console for standalone app can be run by following command
```
$ raremap console  # or simply run `raremap c`
```

Advanced RareMap use

Seperate databases into groups (highly recommended)

her_group:
  -
    db1:
      adapter: sqlite3
      database: db/db1.sqlite3
  -
    db2:
      adapter: sqlite3
      database: db/db1.sqlite3

his_group:
  -
    db1:
      adapter: sqlite3
      database: db/db3.sqlite3
  -
    db2:
      adapter: sqlite3
      database: db/db4.sqlite3

There are benefits by separating databases into groups

Associations are built between databases within a group
Group name is treated as a module namespace
Models of a group are organized within a folder

If all your data reside in several legacy databases, it is important to build back those associations across databases

If there are 2 or more tables with the same name, giving them group names could avoid naming collision

If there are tons of tables, it is better to organize them well

Set up RareMap Options

rare_map_opts:
  foreign_key:
    suffix: fk
    alias:
      abnormal_fk1: table1
      abnormal_fk2: table2
  primary_key:
    table1: abnormal_pk

rare_map_opts[suffix]: If your foreign keys are not ended with ‘id’, you can specify the suffix you want here
rare_map_opts[alias]: If naming convention is not followed by some foreign keys, you can list them here
rare_map_opts: Usually rare_map can identify the primary key of a table, if it fails, please list primary keys here

RareMap Options Precedence

You can place rare_map options in 3 ways

rare_map_opts:             # Global options
  ...
group1:
  -
    rare_map_opts:         # Group options
      ...
  -
    db1:
      ...
legacy_db:
  adapter: sqlite3
  database: db/db.sqlite3
  rare_map_opts:           # DB options
    ...

Precedence: DB > Group > Global

Contributing to rare_map

Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet.
Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it.
Fork the project.
Start a feature/bugfix branch.
Commit and push until you are happy with your contribution.
Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.