Class: SQL::Maker::Select::Oracle

Inherits:
SQL::Maker::Select show all
Defined in:
lib/sql/maker/select/oracle.rb

Instance Attribute Summary

Attributes inherited from SQL::Maker::Select

#auto_bind, #for_update, #from, #group_by, #having, #index_hint, #joins, #name_sep, #new_line, #order_by, #quote_char, #select, #select_map, #select_map_reverse, #strict, #subqueries, #where

Instance Method Summary collapse

Methods inherited from SQL::Maker::Select

#_add_index_hint, #_quote, #add_from, #add_group_by, #add_having, #add_index_hint, #add_join, #add_order_by, #add_select, #add_where, #add_where_raw, #as_sql_for_update, #as_sql_group_by, #as_sql_having, #as_sql_limit, #as_sql_order_by, #as_sql_where, #bind, #distinct, #initialize, #limit, #new_condition, #offset, #prefix, #set_where

Methods included from Util

#array_wrap, #bind_param, bind_param, #croak, included, #parse_args, #quote_identifier, quote_identifier

Constructor Details

This class inherits a constructor from SQL::Maker::Select

Instance Method Details

#as_limit ⇒ Object

Oracle doesn’t have the LIMIT clause.



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# File 'lib/sql/maker/select/oracle.rb', line 5

def as_limit
  return ''
end

#as_sql ⇒ Object

Override as_sql to emulate the LIMIT clause.



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# File 'lib/sql/maker/select/oracle.rb', line 10

def as_sql
  limit  = self.limit
  offset = self.offset

  if limit && offset
    self.add_select( "ROW_NUMBER() OVER (ORDER BY 1) R" )
  end

  sql = super

  if limit
    sql = "SELECT * FROM ( #{sql} ) WHERE "
    if offset
      sql = sql + " R BETWEEN #{offset} + 1 AND #{limit} + #{offset}"
    else
      sql = sql + " rownum <= #{limit}"
    end
  end
  return sql
end