a
    LcòfŒ;  ã                   @   sä   d Z ddlZddlZddlZddlmZ ddlmZ ddlm	Z	m
Z
mZ ddlmZ ddlmZ e d¡Zed	d
ƒZdd„ ZG dd„ dejƒZG dd„ dƒZG dd„ dƒZG dd„ dƒZddd„Zdd„ Zdd„ ZG dd„ dƒZdS )zî
Various data structures used in query construction.

Factored out from django.db.models.query to avoid making the main module very
large and/or so that they can be used by other modules without getting into
circular import difficulties.
é    N)Ú
namedtuple)Ú
FieldError)ÚDEFAULT_DB_ALIASÚDatabaseErrorÚconnections)Ú
LOOKUP_SEP)Útreeúdjango.db.modelsÚPathInfozGfrom_opts to_opts target_fields join_field m2m direct filtered_relationc                 c   s&   | V  |   ¡ D ]}t|ƒE d H  qd S ©N)Ú__subclasses__Ú
subclasses©ÚclsÚsubclass© r   úY/home/httpd/docs/test/DocsMgr/lib/python3.9/site-packages/django/db/models/query_utils.pyr      s    r   c                       sŠ   e Zd ZdZdZdZdZeZdZdddœ‡ fd	d
„
Z	dd„ Z
dd„ Zdd„ Zdd„ Zdd„ Zddd„Zdd„ Zefdd„Zdd„ Z‡  ZS )ÚQze
    Encapsulate filters as objects that can then be combined logically (using
    `&` and `|`).
    ÚANDÚORÚXORTNF)Ú
_connectorÚ_negatedc                   s&   t ƒ jg |¢t| ¡ ƒ¢||d� d S )N)ÚchildrenÚ	connectorÚnegated)ÚsuperÚ__init__ÚsortedÚitems)Úselfr   r   ÚargsÚkwargs©Ú	__class__r   r   r   0   s
    ýz
Q.__init__c                 C   sb   t |ddƒdu rt|ƒ‚| s$| ¡ S |s:t|tƒr:|  ¡ S | j|d�}| | |¡ | ||¡ |S )NÚconditionalF)r   )ÚgetattrÚ	TypeErrorÚcopyÚ
isinstancer   ÚcreateÚadd)r    ÚotherÚconnÚobjr   r   r   Ú_combine7   s    z
Q._combinec                 C   s   |   || j¡S r   )r/   r   ©r    r,   r   r   r   Ú__or__D   s    zQ.__or__c                 C   s   |   || j¡S r   )r/   r   r0   r   r   r   Ú__and__G   s    z	Q.__and__c                 C   s   |   || j¡S r   )r/   r   r0   r   r   r   Ú__xor__J   s    z	Q.__xor__c                 C   s   |   ¡ }| ¡  |S r   )r(   Únegate)r    r.   r   r   r   Ú
__invert__M   s    zQ.__invert__c                 C   s(   |j | ||dd|d�\}}| |¡ |S )NF)Úallow_joinsZ
split_subqZcheck_filterableÚ	summarize)Z_add_qZpromote_joins)r    Úqueryr6   Úreuser7   Zfor_saveZclauseZjoinsr   r   r   Úresolve_expressionR   s    ú

zQ.resolve_expressionc                 c   sH   | V  | j D ]6}t|tƒr"|d }t|dƒr<| ¡ E dH  q|V  qdS )zg
        Recursively yield this Q object and all subexpressions, in depth-first
        order.
        é   ÚflattenN)r   r)   ÚtupleÚhasattrr<   )r    Úchildr   r   r   r<   b   s    


z	Q.flattenc              
   C   s
  ddl m}m} ddlm} ddlm} ddlm} |dƒ}| 	¡ D ]*\}	}
t
|
dƒs^||
ƒ}
|j|
|	dd	� qD| |d
ƒd¡ t| jjr¨| t|| d|ƒ d�ƒ¡ n
| | ¡ |j|d�}z| |¡duW S  t�y } zt d| |¡ W Y d}~dS d}~0 0 dS )z|
        Do a database query to check if the expressions of the Q instance
        matches against the expressions.
        r   )ÚBooleanFieldÚValue)ÚCoalesce)ÚQuery)ÚSINGLENr:   F)Úselectr;   Ú_checkT)Úoutput_field)Úusingz.Got a database error calling check() on %r: %s)Zdjango.db.modelsr@   rA   Zdjango.db.models.functionsrB   Zdjango.db.models.sqlrC   Zdjango.db.models.sql.constantsrD   r   r>   Zadd_annotationr   ÚfeaturesZsupports_comparing_boolean_exprZadd_qr   Zget_compilerZexecute_sqlr   ÚloggerÚwarning)r    ZagainstrH   r@   rA   rB   rC   rD   r8   ÚnameÚvalueÚcompilerÚer   r   r   Úcheckq   s&    

zQ.checkc                 C   sf   d| j j| j jf }| d¡r*| dd¡}t| jƒ}i }| j| jkrN| j|d< | j	r\d|d< |||fS )Nz%s.%szdjango.db.models.query_utilsr	   r   Tr   )
r$   Ú
__module__Ú__name__Ú
startswithÚreplacer=   r   r   Údefaultr   )r    Úpathr!   r"   r   r   r   ÚdeconstructŽ   s    


zQ.deconstruct)NTNFF)rR   rQ   Ú__qualname__Ú__doc__r   r   r   rU   r%   r   r/   r1   r2   r3   r5   r:   r<   r   rP   rW   Ú__classcell__r   r   r#   r   r   #   s"    ÿ
r   c                   @   s*   e Zd ZdZdd„ Zd	dd„Zdd„ ZdS )
ÚDeferredAttributez„
    A wrapper for a deferred-loading field. When the value is read from this
    object the first time, the query is executed.
    c                 C   s
   || _ d S r   )Úfield)r    r\   r   r   r   r   ¡   s    zDeferredAttribute.__init__Nc                 C   sT   |du r| S |j }| jj}||vrL|  |¡}|du rD|j|gd� n|||< || S )zx
        Retrieve and caches the value from the datastore on the first lookup.
        Return the cached value.
        N)Úfields)Ú__dict__r\   ÚattnameÚ_check_parent_chainZrefresh_from_db)r    Úinstancer   ÚdataÚ
field_nameÚvalr   r   r   Ú__get__¤   s    
zDeferredAttribute.__get__c                 C   s6   |j }| | jj¡}| jjr2| j|kr2t||jƒS dS )zÁ
        Check if the field value can be fetched from a parent field already
        loaded in the instance. This can be done if the to-be fetched
        field is a primary key field.
        N)Ú_metaZget_ancestor_linkr\   ÚmodelÚprimary_keyr&   r_   )r    ra   ÚoptsZ
link_fieldr   r   r   r`   ·   s
    z%DeferredAttribute._check_parent_chain)N)rR   rQ   rX   rY   r   re   r`   r   r   r   r   r[   ›   s   
r[   c                   @   s    e Zd ZdZdd„ Zdd„ ZdS )Úclass_or_instance_methodzŒ
    Hook used in RegisterLookupMixin to return partial functions depending on
    the caller type (instance or class of models.Field).
    c                 C   s   || _ || _d S r   )Úclass_methodÚinstance_method)r    rk   rl   r   r   r   r   Ê   s    z!class_or_instance_method.__init__c                 C   s$   |d u rt  | j|¡S t  | j|¡S r   )Ú	functoolsÚpartialrk   rl   )r    ra   Úownerr   r   r   re   Î   s    z class_or_instance_method.__get__N)rR   rQ   rX   rY   r   re   r   r   r   r   rj   Ä   s   rj   c                   @   s¶   e Zd Zdd„ Zejdd�dd„ ƒZdd„ ZeeeƒZ	e
eƒZd	d
„ Zdd„ Zedd„ ƒZe
dd„ ƒZddd„Zddd„ZeeeƒZe
eƒZddd„Zddd„ZeeeƒZe
eƒZdS )ÚRegisterLookupMixinc                 C   s   |   ¡  |d ¡S r   )Úget_lookupsÚget)r    Úlookup_namer   r   r   Ú_get_lookupÕ   s    zRegisterLookupMixin._get_lookupN)Úmaxsizec                 C   s   dd„ t  | ¡D ƒ}|  |¡S )Nc                 S   s   g | ]}|j  d i ¡‘qS )Úclass_lookups)r^   rr   )Ú.0Úparentr   r   r   Ú
<listcomp>Ú   s   z9RegisterLookupMixin.get_class_lookups.<locals>.<listcomp>)ÚinspectÚgetmroÚmerge_dicts)r   rv   r   r   r   Úget_class_lookupsØ   s    ÿz%RegisterLookupMixin.get_class_lookupsc                 C   s(   |   ¡ }t| dd ƒ }r$i |¥|¥S |S ©NÚinstance_lookups)r}   r&   )r    rv   r   r   r   r   Úget_instance_lookupsß   s    z(RegisterLookupMixin.get_instance_lookupsc                 C   sN   ddl m} |  |¡}|d u r4t| dƒr4| j |¡S |d urJt||ƒsJd S |S )Nr   )ÚLookuprG   )Údjango.db.models.lookupsr�   rt   r>   rG   Ú
get_lookupÚ
issubclass)r    rs   r�   Úfoundr   r   r   rƒ   è   s    
zRegisterLookupMixin.get_lookupc                 C   sN   ddl m} |  |¡}|d u r4t| dƒr4| j |¡S |d urJt||ƒsJd S |S )Nr   )Ú	TransformrG   )r‚   r†   rt   r>   rG   Úget_transformr„   )r    rs   r†   r…   r   r   r   r‡   ò   s    
z!RegisterLookupMixin.get_transformc                 C   s    i }t | ƒD ]}| |¡ q|S )z«
        Merge dicts in reverse to preference the order of the original list. e.g.,
        merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
        )ÚreversedÚupdate)ZdictsÚmergedÚdr   r   r   r|   ü   s    zRegisterLookupMixin.merge_dictsc                 C   s   t | ƒD ]}|j ¡  qd S r   )r   r}   Úcache_clearr   r   r   r   Ú_clear_cached_class_lookups  s    z/RegisterLookupMixin._clear_cached_class_lookupsc                 C   s4   |d u r|j }d| jvri | _|| j|< |  ¡  |S )Nrv   )rs   r^   rv   r�   ©r   Úlookuprs   r   r   r   Úregister_class_lookup  s    

z)RegisterLookupMixin.register_class_lookupc                 C   s,   |d u r|j }d| jvri | _|| j|< |S r~   )rs   r^   r   ©r    r�   rs   r   r   r   Úregister_instance_lookup  s    

z,RegisterLookupMixin.register_instance_lookupc                 C   s"   |du r|j }| j|= |  ¡  dS )zn
        Remove given lookup from cls lookups. For use in tests only as it's
        not thread-safe.
        N)rs   rv   r�   rŽ   r   r   r   Ú_unregister_class_lookup"  s    z,RegisterLookupMixin._unregister_class_lookupc                 C   s   |du r|j }| j|= dS )zs
        Remove given lookup from instance lookups. For use in tests only as
        it's not thread-safe.
        N)rs   r   r‘   r   r   r   Ú_unregister_instance_lookup,  s    z/RegisterLookupMixin._unregister_instance_lookup)N)N)N)N)rR   rQ   rX   rt   rm   Ú	lru_cacher}   r€   rj   rq   Úclassmethodrƒ   r‡   Ústaticmethodr|   r�   r�   r’   Zregister_lookupr“   r”   Z_unregister_lookupr   r   r   r   rp   Ô   s0   








	
ÿ


	ÿrp   Fc                 C   sŽ   | j s
dS | j jr|sdS |rD|r2|  ¡ |vr2dS |sD| j|vrDdS |sR| jrRdS |rŠ|rŠ| j|v rŠ| |vrŠtd| jjj› d| j› d�ƒ‚dS )af  
    Return True if this field should be used to descend deeper for
    select_related() purposes. Used by both the query construction code
    (compiler.get_related_selections()) and the model instance creation code
    (compiler.klass_info).

    Arguments:
     * field - the field to be checked
     * restricted - a boolean field, indicating if the field list has been
       manually restricted using a requested clause)
     * requested - The select_related() dictionary.
     * select_mask - the dictionary of selected fields.
     * reverse - boolean, True if we are checking a reverse select related
    FzField Ú.zM cannot be both deferred and traversed using select_related at the same time.T)	Zremote_fieldZparent_linkZrelated_query_namerL   Únullr   rg   rf   Zobject_name)r\   Z
restrictedÚ	requestedZselect_maskÚreverser   r   r   Úselect_related_descend;  s.    
ÿþýüÿrœ   c                 C   sL   t dt| ƒd ƒD ]4}t | d|… ¡}| |¡r|| |d… f  S qdS )zÕ
    Check if the lookup_parts contains references to the given annotations set.
    Because the LOOKUP_SEP is contained in the default annotation names, check
    each prefix of the lookup_parts for a match.
    r;   r   N)Nr   )ÚrangeÚlenr   Újoinrr   )Zlookup_partsÚannotationsÚnZlevel_n_lookupr   r   r   Úrefs_expressionb  s
    
r¢   c                    s,   ‡ fdd„}||ƒp*t |ddƒo*||jjƒS )zÞ
    Check that self.model is compatible with target_opts. Compatibility
    is OK if:
      1) model and opts match (where proxy inheritance is removed)
      2) model is parent of opts' model or the other way around
    c                    s*   ˆ j j| jkp(| jˆ j  ¡ v p(ˆ |  ¡ v S r   )rf   Zconcrete_modelZget_parent_list)ri   ©rg   r   r   rP   w  s
    ÿ
ýz-check_rel_lookup_compatibility.<locals>.checkrh   F)r&   rg   rf   )rg   Ztarget_optsr\   rP   r   r£   r   Úcheck_rel_lookup_compatibilityo  s    ÿr¤   c                   @   s@   e Zd ZdZeƒ dœdd„Zdd„ Zdd„ Zd	d
„ Zdd„ Z	dS )ÚFilteredRelationz7Specify custom filtering in the ON clause of SQL joins.©Ú	conditionc                C   s:   |st dƒ‚|| _d | _t|tƒs*t dƒ‚|| _g | _d S )Nzrelation_name cannot be empty.z*condition argument must be a Q() instance.)Ú
ValueErrorÚrelation_nameÚaliasr)   r   r§   rV   )r    r©   r§   r   r   r   r   �  s    
zFilteredRelation.__init__c                 C   s4   t || jƒstS | j|jko2| j|jko2| j|jkS r   )r)   r$   ÚNotImplementedr©   rª   r§   r0   r   r   r   Ú__eq__™  s    
ÿ
ýzFilteredRelation.__eq__c                 C   s,   t | j| jd�}| j|_| jd d … |_|S )Nr¦   )r¥   r©   r§   rª   rV   )r    Úcloner   r   r   r­   ¢  s    zFilteredRelation.clonec                 O   s   t dƒ‚dS )zz
        QuerySet.annotate() only accepts expression-like arguments
        (with a resolve_expression() method).
        z0FilteredRelation.resolve_expression() is unused.N)ÚNotImplementedError)r    r!   r"   r   r   r   r:   ¨  s    z#FilteredRelation.resolve_expressionc                 C   s&   |j }|j| jt| jƒd�}| |¡S )N)r9   )r8   Zbuild_filtered_relation_qr§   ÚsetrV   Úcompile)r    rN   Ú
connectionr8   Úwherer   r   r   Úas_sql¯  s    zFilteredRelation.as_sqlN)
rR   rQ   rX   rY   r   r   r¬   r­   r:   r³   r   r   r   r   r¥   Œ  s   
	r¥   )F)rY   rm   rz   ÚloggingÚcollectionsr   Zdjango.core.exceptionsr   Z	django.dbr   r   r   Zdjango.db.models.constantsr   Zdjango.utilsr   Ú	getLoggerrJ   r
   r   ÚNoder   r[   rj   rp   rœ   r¢   r¤   r¥   r   r   r   r   Ú<module>   s,   
þx)g
'