o ןi;@sdZddlZddlZddlZddlmZddlmZddlm Z m Z m Z ddl m Z ddlmZedZed d Zd d ZGd ddejZGdddZGdddZGdddZdddZddZddZGdddZdS)z 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. N) namedtuple) FieldError)DEFAULT_DB_ALIAS DatabaseError connections) LOOKUP_SEP)treedjango.db.modelsPathInfozGfrom_opts to_opts target_fields join_field m2m direct filtered_relationccs(|V|D] }t|EdHqdSN)__subclasses__ subclassesclssubclassrfC:\Users\psant\Downloads\Anu Raj Backend\school\venv\Lib\site-packages\django/db/models/query_utils.pyr s  r cseZdZdZdZdZdZeZdZdddfd d Z d d Z d dZ ddZ ddZ ddZ dddZddZefddZddZZS)Qze Encapsulate filters as objects that can then be combined logically (using `&` and `|`). ANDORXORTNF) _connector_negatedcs&tjg|t|||ddS)N)children connectornegated)super__init__sorteditems)selfrrargskwargs __class__rrr0s  z Q.__init__cCsbt|dddur t||s|S|st|tr|S|j|d}|||||||S)N conditionalF)r)getattr TypeErrorcopy isinstancercreateadd)r otherconnobjrrr_combine7s   z Q._combinecC|||jSr )r/rr r,rrr__or__DzQ.__or__cCr0r )r/rr1rrr__and__Gr3z Q.__and__cCr0r )r/rr1rrr__xor__Jr3z Q.__xor__cCs|}||Sr )r(negate)r r.rrr __invert__Msz Q.__invert__cCs(|j|||dd|d\}}|||S)NF) allow_joinsZ split_subqZcheck_filterable summarize)Z_add_qZ promote_joins)r queryr8reuser9Zfor_saveZclauseZjoinsrrrresolve_expressionRs zQ.resolve_expressionccsJ|V|jD]}t|tr|d}t|dr|EdHq|VqdS)zg Recursively yield this Q object and all subexpressions, in depth-first order. flattenN)rr)tuplehasattrr>)r childrrrr>bs   z Q.flattenc Csddlm}m}ddlm}ddlm}ddlm}|d}| D]\} } t | ds/|| } |j | | dd q"| |d d t |j jrT|t||d |d n|||j|d} z| |duWSty} ztd|| WYd} ~ d Sd} ~ ww)z| Do a database query to check if the expressions of the Q instance matches against the expressions. r) BooleanFieldValue)Coalesce)Query)SINGLENr<F)selectr=_checkT) output_field)usingz.Got a database error calling check() on %r: %s)Zdjango.db.modelsrBrCZdjango.db.models.functionsrDZdjango.db.models.sqlrEZdjango.db.models.sql.constantsrFrr@Zadd_annotationrfeaturesZsupports_comparing_boolean_exprZadd_qrZ get_compilerZ execute_sqlrloggerwarning) r ZagainstrJrBrCrDrErFr:namevaluecompilererrrcheckqs*       zQ.checkcCsfd|jj|jjf}|dr|dd}t|j}i}|j|jkr'|j|d<|j r.d|d<|||fS)Nz%s.%szdjango.db.models.query_utilsr rTr) r$ __module____name__ startswithreplacer?rrdefaultr)r pathr!r"rrr deconstructs      z Q.deconstruct)NTNFF)rTrS __qualname____doc__rrrrWr%rr/r2r4r5r7r<r>rrRrY __classcell__rrr#rr#s$   rc@s*eZdZdZddZd ddZddZdS) DeferredAttributez A wrapper for a deferred-loading field. When the value is read from this object the first time, the query is executed. cCs ||_dSr )field)r r^rrrrs zDeferredAttribute.__init__NcCsZ|dur|S|j}|jj}||vr)||}|dur%|j|gd||S|||<||S)zx Retrieve and caches the value from the datastore on the first lookup. Return the cached value. N)fields)__dict__r^attname_check_parent_chainZrefresh_from_db)r instancerdata field_namevalrrr__get__s zDeferredAttribute.__get__cCs6|j}||jj}|jjr|j|krt||jSdS)z 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)_metaZget_ancestor_linkr^model primary_keyr&ra)r rcoptsZ link_fieldrrrrbs  z%DeferredAttribute._check_parent_chainr )rTrSrZr[rrgrbrrrrr]s   r]c@s eZdZdZddZddZdS)class_or_instance_methodz Hook used in RegisterLookupMixin to return partial functions depending on the caller type (instance or class of models.Field). cCs||_||_dSr ) class_methodinstance_method)r rmrnrrrrs z!class_or_instance_method.__init__cCs$|dur t|j|St|j|Sr ) functoolspartialrmrn)r rcownerrrrrgsz class_or_instance_method.__get__N)rTrSrZr[rrgrrrrrls rlc@seZdZddZejddddZddZeeeZ e eZd d Z d d Z e d dZe ddZdddZdddZeeeZe eZdddZdddZeeeZe eZdS)RegisterLookupMixincCs||dSr ) get_lookupsget)r lookup_namerrr _get_lookupszRegisterLookupMixin._get_lookupN)maxsizecCsddt|D}||S)NcSsg|] }|jdiqS) class_lookups)r`rt).0parentrrr sz9RegisterLookupMixin.get_class_lookups..)inspectgetmro merge_dicts)rrxrrrget_class_lookupss z%RegisterLookupMixin.get_class_lookupscCs(|}t|dd}ri||S|SNinstance_lookups)rr&)r rxrrrrget_instance_lookupss z(RegisterLookupMixin.get_instance_lookupscCNddlm}||}|durt|dr|j|S|dur%t||s%dS|S)Nr)LookuprI)django.db.models.lookupsrrvr@rI get_lookup issubclass)r rurfoundrrrr   zRegisterLookupMixin.get_lookupcCr)Nr) TransformrI)rrrvr@rI get_transformr)r rurrrrrrrz!RegisterLookupMixin.get_transformcCs i}t|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'. N)reversedupdate)Zdictsmergeddrrrr~s  zRegisterLookupMixin.merge_dictscCst|D]}|jqdSr )r r cache_clearrrrr_clear_cached_class_lookupss  z/RegisterLookupMixin._clear_cached_class_lookupscCs4|dur|j}d|jvri|_||j|<||S)Nrx)rur`rxrrlookuprurrrregister_class_lookup s  z)RegisterLookupMixin.register_class_lookupcCs,|dur|j}d|jvri|_||j|<|Sr)rur`rr rrurrrregister_instance_lookups   z,RegisterLookupMixin.register_instance_lookupcCs"|dur|j}|j|=|dS)zn Remove given lookup from cls lookups. For use in tests only as it's not thread-safe. N)rurxrrrrr_unregister_class_lookup"s z,RegisterLookupMixin._unregister_class_lookupcCs|dur|j}|j|=dS)zs Remove given lookup from instance lookups. For use in tests only as it's not thread-safe. N)rurrrrr_unregister_instance_lookup,s z/RegisterLookupMixin._unregister_instance_lookupr )rTrSrZrvro lru_cacherrrlrs classmethodrr staticmethodr~rrrZregister_lookuprrZ_unregister_lookuprrrrrrs2            rrFcCs|jsdS|jjr |s dS|r"|r||vrdS|s"|j|vr"dS|s)|jr)dS|rE|rE|j|vrE||vrEtd|jjjd|jddS)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 FzField .zM cannot be both deferred and traversed using select_related at the same time.TN) Z remote_fieldZ parent_linkZrelated_query_namerNnullrrirhZ object_name)r^Z restricted requestedZ select_maskreverserrrselect_related_descend;s.  rcCsLtdt|dD]}t|d|}||r#|||dfSq dS)z 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=rN)Nr)rangelenrjoinrt)Z lookup_parts annotationsnZlevel_n_lookuprrrrefs_expressionbs  rcs,fdd}||pt|ddo||jjS)z 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 cs*jj|jkp|jjvp|vSr )rhZconcrete_modelZget_parent_list)rkrirrrRws  z-check_rel_lookup_compatibility..checkrjFN)r&rirh)riZ target_optsr^rRrrrcheck_rel_lookup_compatibilityos rc@s@eZdZdZedddZddZddZd d Zd d Z d S)FilteredRelationz7Specify custom filtering in the ON clause of SQL joins. conditioncCs:|std||_d|_t|tstd||_g|_dS)Nzrelation_name cannot be empty.z*condition argument must be a Q() instance.) ValueError relation_namealiasr)rrrX)r rrrrrrs  zFilteredRelation.__init__cCs4t||jstS|j|jko|j|jko|j|jkSr )r)r$NotImplementedrrrr1rrr__eq__s    zFilteredRelation.__eq__cCs,t|j|jd}|j|_|jdd|_|S)Nr)rrrrrX)r clonerrrrszFilteredRelation.clonecOstd)zz QuerySet.annotate() only accepts expression-like arguments (with a resolve_expression() method). z0FilteredRelation.resolve_expression() is unused.N)NotImplementedError)r r!r"rrrr<sz#FilteredRelation.resolve_expressioncCs&|j}|j|jt|jd}||S)N)r;)r:Zbuild_filtered_relation_qrsetrXcompile)r rP connectionr:whererrras_sqls zFilteredRelation.as_sqlN) rTrSrZr[rrrrr<rrrrrrs   r)F)r[ror|logging collectionsrZdjango.core.exceptionsrZ django.dbrrrZdjango.db.models.constantsrZ django.utilsr getLoggerrLr r Noderr]rlrrrrrrrrrrs.     x) g'