U
    Ha                     @   sR   d Z ddlmZmZ G dd deZG dd dZG dd dZG d	d
 d
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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_names r   G/tmp/pip-unpacked-wheel-3jxiddxt/django/db/models/sql/datastructures.py__init__   s    zMultiJoin.__init__N)__name__
__module____qualname____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dZdd Zdd Ze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()
    Nc                 C   s8   || _ || _|| _|| _| | _|| _|| _|| _d S r   )	
table_nameparent_aliastable_alias	join_typeZget_joining_columns	join_cols
join_fieldnullablefiltered_relation)r   r   r   r   r   r   r   r   r   r   r	   r
   )   s    
zJoin.__init__c              	   C   s,  g }g }|j }|jj}| jD ]2\}}|d|| j|||| j||f  q| j|j	j
| j| j}	|	r||	\}
}|d|
  || | jr|| j\}
}|
r|d|
  || |st| jd| j}td|j d|}| j| jkrdnd| j }d| j|| j||f }||fS )	z
        Generate 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   %sz%s %s%s ON (%s))quote_name_unless_aliasopsZ
quote_namer   appendr   r   r   Zget_extra_restrictionqueryZwhere_classcompileextendr   getattr
ValueError	__class__joinr   r   )r   compiler
connectionZjoin_conditionsparamsqnZqn2Zlhs_colZrhs_colZ
extra_condZ	extra_sqlZextra_paramsZdeclared_fieldZon_clause_sql	alias_strZsqlr   r   r	   as_sql;   sH    
	  


zJoin.as_sqlc              	      sr     | j| j}  | j| j}| jd k	rN| j } fdd| jjD |_nd }| j| j||| j| j	| j
|dS )Nc                    s   g | ]}  ||qS r   )get).0p
change_mapr   r	   
<listcomp>m   s     z(Join.relabeled_clone.<locals>.<listcomp>)r   )r,   r   r   r   clonepathr$   r   r   r   r   )r   r0   Znew_parent_aliasZnew_table_aliasr   r   r/   r	   relabeled_cloneh   s    

     zJoin.relabeled_clonec                 C   s   | j | j| j| j| jfS r   )r$   r   r   r   r   r   r   r   r	   identityu   s    zJoin.identityc                 C   s   t |tstS | j|jkS r   )
isinstancer   NotImplementedr6   r   otherr   r   r	   __eq__   s    
zJoin.__eq__c                 C   s
   t | jS r   hashr6   r5   r   r   r	   __hash__   s    zJoin.__hash__c                 C   s(   |r| |kS | j d d |j d d kS )Nr6   r   r:   Zwith_filtered_relationr   r   r	   equals   s    zJoin.equalsc                 C   s   |  i }t|_|S r   )r4   r   r   r   newr   r   r	   demote   s    
zJoin.demotec                 C   s   |  i }t|_|S r   )r4   r   r   rC   r   r   r	   promote   s    
zJoin.promote)N)r   r   r   r   r
   r+   r4   propertyr6   r;   r>   rB   rE   rF   r   r   r   r	   r      s    
-
	r   c                   @   sX   e Zd ZdZdZdZdZdd Zdd Zdd Z	e
d	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 r   )r   r   )r   r   aliasr   r   r	   r
      s    zBaseTable.__init__c                 C   s2   | j | jkrdnd| j  }|| j}|| g fS )Nr   r   )r   r   r   )r   r&   r'   r*   Zbase_sqlr   r   r	   r+      s    zBaseTable.as_sqlc                 C   s   |  | j|| j| jS r   )r$   r   r,   r   )r   r0   r   r   r	   r4      s    zBaseTable.relabeled_clonec                 C   s   | j | j| jfS r   )r$   r   r   r5   r   r   r	   r6      s    zBaseTable.identityc                 C   s   t |tstS | j|jkS r   )r7   rH   r8   r6   r9   r   r   r	   r;      s    
zBaseTable.__eq__c                 C   s
   t | jS r   r<   r5   r   r   r	   r>      s    zBaseTable.__hash__c                 C   s   | j |j kS r   r@   rA   r   r   r	   rB      s    zBaseTable.equals)r   r   r   r   r   r   r   r
   r+   r4   rG   r6   r;   r>   rB   r   r   r   r	   rH      s   
rH   N)	r   Zdjango.db.models.sql.constantsr   r   	Exceptionr   r   r   rH   r   r   r   r	   <module>   s
   