Class: SQL

Inherits:

Object

• Object
• SQL

Defined in:

lib/eno.rb

Constant Summary

H_EMPTY =

{}.freeze

Instance Method Summary

• #_q(expr) ⇒ Object
• #all(sym = nil) ⇒ Object
• #default_select ⇒ Object
• #from(*members, **props) ⇒ Object
• #initialize(ctx) ⇒ SQL constructor

  A new instance of SQL.

• #limit(*members) ⇒ Object
• #method_missing(sym, *args) ⇒ Object
• #order_by(*members, **props) ⇒ Object
• #select(*members, **props) ⇒ Object
• #to_sql(&block) ⇒ Object
• #where(expr) ⇒ Object
• #window(sym, &block) ⇒ Object
• #with(*members, **props) ⇒ Object

Constructor Details

#initialize(ctx) ⇒ SQL

Returns a new instance of SQL.

# File 'lib/eno.rb', line 402

def initialize(ctx)
  @ctx = ctx
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args) ⇒ Object

# File 'lib/eno.rb', line 427

def method_missing(sym, *args)
  if @ctx.has_key?(sym)
    value = @ctx[sym]
    return Symbol === value ? Identifier.new(value) : value
  end
  
  super if sym == :to_hash
  if args.empty?
    Identifier.new(sym)
  else
    FunctionCall.new(sym, *args)
  end
end

Instance Method Details

#_q(expr) ⇒ Object

# File 'lib/eno.rb', line 419

def _q(expr)
  QuotedExpression.new(expr)
end

#all(sym = nil) ⇒ Object

# File 'lib/eno.rb', line 479

def all(sym = nil)
  if sym
    Identifier.new("#{sym}.*")
  else
    Identifier.new('*')
  end
end

#default_select ⇒ Object

# File 'lib/eno.rb', line 423

def default_select
  Select.new(:*)
end

#from(*members, **props) ⇒ Object

# File 'lib/eno.rb', line 455

def from(*members, **props)
  @from = From.new(*members, **props)
end

#limit(*members) ⇒ Object

# File 'lib/eno.rb', line 475

def limit(*members)
  @limit = Limit.new(*members)
end

#order_by(*members, **props) ⇒ Object

# File 'lib/eno.rb', line 471

def order_by(*members, **props)
  @order_by = OrderBy.new(*members, **props)
end

#select(*members, **props) ⇒ Object

# File 'lib/eno.rb', line 447

def select(*members, **props)
  if members.empty? && !props.empty?
    members = props.map { |k, v| Alias.new(v, k) }
    props = {}
  end
  @select = Select.new(*members, **props)
end

#to_sql(&block) ⇒ Object

# File 'lib/eno.rb', line 406

def to_sql(&block)
  instance_eval(&block)
  [
    @with,
    @select || default_select,
    @from,
    @where,
    @window,
    @order_by,
    @limit
  ].compact.map { |c| c.to_sql }.join(' ')
end

#where(expr) ⇒ Object

# File 'lib/eno.rb', line 459

def where(expr)
  if @where
    @where.members << expr
  else
    @where = Where.new(expr)
  end
end

#window(sym, &block) ⇒ Object

# File 'lib/eno.rb', line 467

def window(sym, &block)
  @window = Window.new(sym, &block)
end

#with(*members, **props) ⇒ Object

# File 'lib/eno.rb', line 441

def with(*members, **props)
  @with = With.new(*members, **props)
end