Method: SQL::Maker::Select#as_sql

Defined in:

lib/sql/maker/select.rb

#as_sql ⇒ Object

# File 'lib/sql/maker/select.rb', line 155

def as_sql
  sql = ''
  new_line = self.new_line
 
  unless self.select.empty?
    sql += self.prefix
    sql += 'DISTINCT ' if self.distinct
    sql += self.select.map {|col|
      as = self.select_map[col]
      col = col.respond_to?(:as_sql) ? col.as_sql : self._quote(col)
      next col if as.nil?
      as = as.respond_to?(:as_sql) ? as.as_sql : self._quote(as)
      if as && col =~ /(?:^|\.)#{Regexp.escape(as)}$/
        col
      else
        col + ' AS ' +  as
      end
    }.join(', ') + new_line
  end

  sql += 'FROM '

  ## Add any explicit JOIN statements before the non-joined tables.
  unless self.joins.empty?
    initial_table_written = 0
    self.joins.each do |j|
      table = j[:table]
      join  = j[:joins]
      table = self._add_index_hint(table); ## index hint handling
      sql += table if initial_table_written == 0
      initial_table_written += 1
      sql += ' ' + join[:type].upcase if join[:type]
      sql += ' JOIN ' + self._quote(join[:table])
      sql += ' ' + self._quote(join[:alias]) if join[:alias]

      if condition = join[:condition]
        if condition.is_a?(Array)
          sql += ' USING (' + condition.map {|e| self._quote(e) }.join(', ') + ')'
        elsif condition.is_a?(Hash)
          conds = []
          condition.keys.each do |key|
            conds += [self._quote(key) + ' = ' + self._quote(condition[key])]
          end
          sql += ' ON ' + conds.join(' AND ')
        else
          sql += ' ON ' + condition
        end
      end
    end
    sql += ', ' unless self.from.empty?
  end

  unless self.from.empty?
    sql += self.from.map {|e| self._add_index_hint(e[0], e[1]) }.join(', ')
  end

  sql += new_line
  sql += self.as_sql_where     if self.where

  sql += self.as_sql_group_by  if self.group_by
  sql += self.as_sql_having    if self.having
  sql += self.as_sql_order_by  if self.order_by

  sql += self.as_sql_limit     if self.limit

  sql += self.as_sql_for_update
  sql.gsub!(/#{new_line}+$/, '')

  @auto_bind ? bind_param(sql, self.bind) : sql
end