Class: Criteria

Inherits:
Object
  • Object
show all
Defined in:
lib/criteria.rb

Overview

Criteria is a collection of Criterion as well as additional constraints regarding the order, limit and offset

see the readme for usage examples.

Defined Under Namespace

Modules: VERSION Classes: Association, Column, Criterion, ManyToOneAssociation, NotCriterion, OneToManyAssociation, Order

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(c = nil) {|_self| ... } ⇒ Criteria

Create a new criteria, optionally pass in a Criterion object You can also pass a block, and self will be yielded

Yields:

  • (_self)

Yield Parameters:

  • _self (Criteria) —

    the object that the method was called on



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# File 'lib/criteria.rb', line 20

def initialize(c=nil) # :yields: self
  @and = []
  @or = []
  @order_by = []
  @group_by = []
  @select = []
  @limit = nil
  @offset = nil    
  @joins = []
  @default_operator = :or
self.add(c) if c.is_a? Criterion

  yield(self) if block_given?
end

Instance Attribute Details

#default_operator ⇒ Object

Returns the value of attribute default_operator.



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# File 'lib/criteria.rb', line 16

def default_operator
  @default_operator
end

#limit ⇒ Object

Returns the value of attribute limit.



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# File 'lib/criteria.rb', line 16

def limit
  @limit
end

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'lib/criteria.rb', line 16

def offset
  @offset
end

Instance Method Details

#&(criterion) ⇒ Object

AND this with another criterion



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# File 'lib/criteria.rb', line 92

def &(criterion)
  self.and(criterion)
end

#<<(c) ⇒ Object 



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# File 'lib/criteria.rb', line 70

def <<(c)
  raise "<< does not accept a block, perhaps you were trying to pass it to Criteria.new?" if block_given?
  add(c)
end

#add(c = nil, operator = self.default_operator) {|c = Criteria.new| ... } ⇒ Object

Yields:



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# File 'lib/criteria.rb', line 75

def add(c=nil, operator=self.default_operator)
  yield(c = Criteria.new) if c.nil? and block_given?
    
  # puts "#{self} << OR #{c}"
  if c.is_a? Column
    raise "You cannot directly #{operator.to_s.upcase} an instanceof Column, you must call some sort of expression (eq, ne, gt, ge, etc) on it."
  end
  
  if operator==:or
    @or << c
  else
    @and << c
  end
  self
end

#and(c = nil, &block) ⇒ Object

AND a criterion with the existing Criteria



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# File 'lib/criteria.rb', line 61

def and(c=nil, &block)
  add(c, :and, &block)
end

#ands ⇒ Object

Return a modifiable array of AND’d criteria



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# File 'lib/criteria.rb', line 36

def ands
  @and
end

#associations ⇒ Object 



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# File 'lib/criteria.rb', line 150

def associations
  out = []
  (@and + @or).each do |c| 
    out+=c.associations
  end
  out
end

#columns ⇒ Object

Return a unique list of column objects that are referenced in this query



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# File 'lib/criteria.rb', line 134

def columns
  columns = []
  (@and + @or).each do |c|
   c.columns.each do |c2|
     columns << c2
   end
  end 
  columns.uniq
end

#group_by ⇒ Object

Get the collection of columns to group by



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# File 'lib/criteria.rb', line 51

def group_by
  @group_by
end

#or(c = nil, &block) ⇒ Object

OR a criterion with the existing Criteria



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# File 'lib/criteria.rb', line 66

def or(c=nil, &block)
  add(c, :or, &block)
end

#order_by ⇒ Object

Get the collection of Order objects to order by



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# File 'lib/criteria.rb', line 56

def order_by
  @order_by
end

#ors ⇒ Object

Returns a modifiable array of OR’d criteria



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# File 'lib/criteria.rb', line 41

def ors
  @ors
end

#select ⇒ Object

Returns an array of column’s to be selected



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# File 'lib/criteria.rb', line 46

def select
  @select
end

#tables ⇒ Object

Get a read-only array of all the table names that will be included in this query



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# File 'lib/criteria.rb', line 146

def tables
  columns.collect {|c| c.table_name }.uniq
end

#to_group_by_sql ⇒ Object 



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# File 'lib/criteria.rb', line 125

def to_group_by_sql
  @group_by.size>0 ? @group_by.collect {|g| g.to_s}.join(",") : nil
end

#to_hash ⇒ Object

FIXME: this returns a list of table names in :include, whereas it should contain the relationship names



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# File 'lib/criteria.rb', line 189

def to_hash
  {
    :include => self.associations,
    :conditions => self.to_where_sql,
    :limit => self.limit,
    :offset => self.offset,
    :order => self.to_order_by_sql,
    :group => self.to_group_by_sql,
    :select => self.to_select_sql
  }
end

#to_order_by_sql ⇒ Object 



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# File 'lib/criteria.rb', line 121

def to_order_by_sql
  @order_by.size>0 ? @order_by.collect {|o| o.to_s}.join(",") : nil
end

#to_s ⇒ Object 



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# File 'lib/criteria.rb', line 201

def to_s
  "Criteria(#{to_hash.inspect})"
end

#to_select_sql ⇒ Object 



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# File 'lib/criteria.rb', line 129

def to_select_sql
  @select.size>0 ? @select.collect{|s| s.to_s}.join(",") : nil
end

#to_where_sql ⇒ Object

Convert the AND and OR statements into the WHERE SQL



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# File 'lib/criteria.rb', line 102

def to_where_sql
  and_clauses = []
  
  if @or.size>0
    c = @or.collect {|c| c.to_where_sql}.join(" OR ")
    if @and.size>0
      and_clauses << "(#{c})"
    else
      and_clauses << c
    end
  end
  
  if @and.size>0
    and_clauses << @and.collect {|c| c.to_where_sql}
  end
  
  and_clauses.size>0 ? "(#{and_clauses.join(" AND ")})" : ""
end

#|(criterion) ⇒ Object

OR this with another criterion



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# File 'lib/criteria.rb', line 97

def |(criterion)
  self.or(criterion)
end