module HashSql

Constants

VERSION

Public Class Methods

select_statement(table, options={}) click to toggle source

Creates a SQL Select Statement @param [String] table The table name to select records from

@param [Hash] options Additional options for the query @option options [Array] fields An array of field names to return in the seach result @option options [Hash] filter

The filter to use for searching accounts. The key is the field name
to set the filter on, and the value is the concatenation of the
operator to use for comparison and the value used for comparing.
Example: { email: "='test@abc.com'"}

AND and ORs:
The logical operations between filters can be AND or OR and 
it could be set by setting the key to either "and:" or "or:"
Example: { email: "='test@abc.com", and: {firstname: "='Nick'"} }
Will be translated to email='test@abc.com' AND firstname = 'Nick'

If multiple entries are placed inside an "and:" or "or:" they will
"ANDed" or "ORed" together.
Example: { email: "='test@abc.com", and: {firstname: "='Nick'", lastname: "='DS'"} }
Will be translated to email='test@abc.com' AND (firstname = 'Nick' AND lastname = 'DS')

Example: { email: "='test@abc.com", or: {firstname: "='Nick'", lastname: "='DS'"} }
Will be translated to email='test@abc.com' OR (firstname = 'Nick' OR lastname = 'DS')

NESTING
Example: { email: "='test@abc.com", and: {firstname: "='Nick'", or: {lastname: "='DS'"}} }
Will be translated to:
email='test@abc.com' AND (firstname = 'Nick' OR lastname = 'DS')

@option options [Hash] :order_by The order in which the results are returned. The key is the

field to order on, and the value is :ASC or :DESC

@option options [Number] :limit the number of results to return @return [Hash]

# File lib/hash_sql.rb, line 37
def self.select_statement(table, options={})
  fields = options[:fields]
  order_by = options[:order_by]
  limit = options[:limit]
  filter = options[:filter]
  query = "SELECT #{fields.join(',')} FROM #{table}"

  filter_string = " WHERE #{parse_filter(filter, nil, '')}" unless filter.nil?
  order_string = " ORDER BY #{parse_order_by(order_by)}" unless order_by.nil?
  limit_string = " LIMIT #{limit}" unless limit.nil?        
  
  filter_string ||= ''
  order_string ||= ''
  limit_string ||= ''

  query = query + filter_string + order_string + limit_string
end

Private Class Methods

parse_filter(filter={}, operator, filter_string) click to toggle source

# File lib/hash_sql.rb, line 57
def self.parse_filter(filter={}, operator, filter_string)        
  filter.each_with_index do |(k, v), index|          
    if k == :and || k == :or
      filter_string += "#{k.to_s.upcase} " unless index == 0                 
      filter_string += '(' unless v.count == 1
      filter_string = parse_filter(v, k, filter_string)
      filter_string += ')' unless v.count == 1            
    else            
      filter_string += "#{k}#{v} "            
      if !operator.nil? && index < filter.count - 1 && filter.values[index + 1].class != Hash              
        filter_string += "#{operator.to_s.upcase} "
      end
    end
  end        
  filter_string.rstrip
end

parse_order_by(order_by={}) click to toggle source

# File lib/hash_sql.rb, line 74
def self.parse_order_by(order_by={})
  order_string = ''
  order_by.each_with_index do |(k,v), index|
    if v != :ASC || v != :DESC
      v = :ASC
    end
    order_string += "#{k} #{v.to_s.upcase}"
    order_string += ',' unless index == order_by.count - 1
  end

  order_string
end