Wednesday, December 10th, 2008 | Author:
admin [NOTE: copy and paste from : http://www.symfony-project.org/jobeet/1_2/Propel/en/03 ]
According to the official YAML website, YAML is “is a human friendly data serialization standard for all programming languages”
Put another way, YAML is a simple language to describe data (strings, integers, dates, arrays, and hashes).
In YAML, structure is shown through indentation, sequence items are denoted by a dash, and key/value pairs within a map are separated by a colon. YAML also has a shorthand syntax to describe the same structure with fewer lines, where arrays are explicitly shown with [] and hashes with {}.
By Example, here is a YAML database schema
schema.yml
# config/schema.yml
propel:
jobeet_category:
id: ~
name: { type: varchar(255), required: true }
jobeet_job:
id: ~
category_id: { type: integer, foreignTable: jobeet_category, foreignReference: id, required: true }
type: { type: varchar(255) }
company: { type: varchar(255), required: true }
logo: { type: varchar(255) }
url: { type: varchar(255) }
position: { type: varchar(255), required: true }
location: { type: varchar(255), required: true }
description: { type: longvarchar, required: true }
how_to_apply: { type: longvarchar, required: true }
token: { type: varchar(255), required: true, index: unique }
is_public: { type: boolean, required: true, default: 1 }
is_activated: { type: boolean, required: true, default: 0 }
email: { type: varchar(255), required: true }
expires_at: { type: timestamp, required: true }
created_at: ~
updated_at: ~
jobeet_affiliate:
id: ~
url: { type: varchar(255), required: true }
email: { type: varchar(255), required: true, index: unique }
token: { type: varchar(255), required: true }
is_active: { type: boolean, required: true, default: 0 }
created_at: ~
jobeet_category_affiliate:
category_id: { type: integer, foreignTable: jobeet_category, foreignReference: id, required: true, primaryKey: true, onDelete: cascade }
affiliate_id: { type: integer, foreignTable: jobeet_affiliate, foreignReference: id, required: true, primaryKey: true, onDelete: cascade }
The schema.yml file contains the description of all tables and their columns. Each column is described with the following information:
type: The column type (boolean, tinyint, smallint, integer, bigint, double, float, real, decimal, char, varchar(size), longvarchar, date, time, timestamp, blob, and clob)
required: Set it to true if you want the column to be required
index: Set it to true if you want to create an index for the column or to unique if you want a unique index to be created on the column.
but yes developer might like it for customization and build a genuine one 
