
 X                 @   s   d  Z  d d l m Z m Z Gd d   d e  Z Gd d   d e  Z Gd d   d e  Z Gd	 d
   d
 e  Z	 Gd d   d e  Z
 d S)z]
Useful auxiliary data structures for query construction. Not useful outside
the SQL domain.
    )INNERLOUTERc               @   s   e  Z d  Z d S)EmptyResultSetN)__name__
__module____qualname__ r   r   Q/home/ubuntu/projects/ifolica/build/django/django/db/models/sql/datastructures.pyr      s   r   c               @   s"   e  Z d  Z d Z d d   Z d S)	MultiJoinz
    Used by join construction code to indicate the point at which a
    multi-valued join was attempted (if the caller wants to treat that
    exceptionally).
    c             C   s   | |  _  | |  _ d  S)N)levelZnames_with_path)selfZ	names_posZpath_with_namesr   r   r	   __init__   s    	zMultiJoin.__init__N)r   r   r   __doc__r   r   r   r   r	   r
      s   r
   c               @   s   e  Z d  Z d S)EmptyN)r   r   r   r   r   r   r	   r      s   r   c               @   s^   e  Z d  Z d Z d d   Z d d   Z d d   Z d d	   Z d
 d   Z d d   Z	 d S)Joina  
    Used by sql.Query and sql.SQLCompiler to generate JOIN clauses into the
    FROM entry. For example, the SQL generated could be
        LEFT OUTER JOIN "sometable" T1 ON ("othertable"."sometable_id" = "sometable"."id")

    This class is primarily used in Query.alias_map. All entries in alias_map
    must be Join compatible by providing the following attributes and methods:
        - table_name (string)
        - table_alias (possible alias for the table, can be None)
        - join_type (can be None for those entries that aren't joined from
          anything)
        - parent_alias (which table is this join's parent, can be None similarly
          to join_type)
        - as_sql()
        - relabeled_clone()
    c             C   sI   | |  _  | |  _ | |  _ | |  _ | j   |  _ | |  _ | |  _ d  S)N)
table_nameparent_aliastable_alias	join_typeZget_joining_columns	join_cols
join_fieldnullable)r   r   r   r   r   r   r   r   r   r	   r   -   s    					zJoin.__init__c             C   sv  g  } g  } | j  } | j j } x^ t |  j  D]M \ } \ } }	 | j d | |  j  | |  | |  j  | |	  f  q1 W|  j j	 | j
 j |  j |  j  }
 |
 r | j |
  \ } } | j d |  | j |  n  | st |  j d |  j  } t d | j   n  d j |  } |  j |  j k r=d n
 d |  j } d |  j | |  j  | | f } | | f S)	z
        Generates the full
           LEFT OUTER JOIN sometable ON sometable.somecol = othertable.othercol, params
        clause for this join.
        z%s.%s = %s.%sz(%s)fieldzaJoin generated an empty ON clause. %s did not yield either joining columns or extra restrictions.z AND  z %sz%s %s%s ON (%s))quote_name_unless_aliasopsZ
quote_name	enumerater   appendr   r   r   Zget_extra_restrictionqueryZwhere_classcompileextendgetattr
ValueError	__class__joinr   r   )r   compiler
connectionZjoin_conditionsparamsqnZqn2indexZlhs_colZrhs_colZ
extra_condZ	extra_sqlextra_paramsZdeclared_fieldZon_clause_sql	alias_strZsqlr   r   r	   as_sql>   s2    	"			%"zJoin.as_sqlc             C   sX   | j  |  j |  j  } | j  |  j |  j  } |  j |  j | | |  j |  j |  j  S)N)getr   r   r#   r   r   r   r   )r   
change_mapZnew_parent_aliasZnew_table_aliasr   r   r	   relabeled_cloneg   s
    zJoin.relabeled_clonec             C   sJ   t  | |  j  rF |  j | j k oE |  j | j k oE |  j | j k Sd S)NF)
isinstancer#   r   r   r   )r   otherr   r   r	   __eq__n   s
    zJoin.__eq__c             C   s   |  j  i   } t | _ | S)N)r/   r   r   )r   newr   r   r	   demotew   s    	zJoin.demotec             C   s   |  j  i   } t | _ | S)N)r/   r   r   )r   r3   r   r   r	   promote|   s    	zJoin.promoteN)
r   r   r   r   r   r,   r/   r2   r4   r5   r   r   r   r	   r      s   )	r   c               @   sF   e  Z d  Z d Z d Z d Z d d   Z d d   Z d d   Z d S)		BaseTablez
    The BaseTable class is used for base table references in FROM clause. For
    example, the SQL "foo" in
        SELECT * FROM "foo" WHERE somecond
    could be generated by this class.
    Nc             C   s   | |  _  | |  _ d  S)N)r   r   )r   r   aliasr   r   r	   r      s    	zBaseTable.__init__c             C   sE   |  j  |  j k r d n
 d |  j  } | j |  j  } | | g  f S)Nr   z %s)r   r   r   )r   r%   r&   r+   Zbase_sqlr   r   r	   r,      s    %zBaseTable.as_sqlc             C   s%   |  j  |  j | j |  j |  j   S)N)r#   r   r-   r   )r   r.   r   r   r	   r/      s    zBaseTable.relabeled_clone)	r   r   r   r   r   r   r   r,   r/   r   r   r   r	   r6      s   r6   N)r   Zdjango.db.models.sql.constantsr   r   	Exceptionr   r
   objectr   r   r6   r   r   r   r	   <module>   s   f