3 (h@shdZddlmZmZGdddeZGdddeZGdddeZGd d d eZ Gd d d eZ d S)z] Useful auxiliary data structures for query construction. Not useful outside the SQL domain. )INNERLOUTERc@s eZdZdS)EmptyResultSetN)__name__ __module__ __qualname__rrG/tmp/pip-install-q3hcpn_q/Django/django/db/models/sql/datastructures.pyrsrc@seZdZdZddZdS) 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). cCs||_||_dS)N)levelZnames_with_path)selfZ names_posZpath_with_namesrrr __init__szMultiJoin.__init__N)rrr__doc__r rrrr r sr c@s eZdZdS)EmptyN)rrrrrrr rsrc@s@eZdZdZddZddZddZdd Zd d Zd d Z dS)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() cCs2||_||_||_||_|j|_||_||_dS)N) table_name parent_alias table_alias join_typeZget_joining_columns join_cols join_fieldnullable)r rrrrrrrrr r -s z Join.__init__cCsg}g}|j}|jj}xDt|jD]6\}\}} |jd||j||||j|| fq"W|jj |j j |j|j} | r|j | \} } |jd| |j | |st|jd|j} td| jdj|}|j|jkrdnd|j}d|j||j||f}||fS) 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_aliasopsZ quote_name enumeraterappendrrrZget_extra_restrictionqueryZ where_classcompileextendgetattr ValueError __class__joinrr)r compiler connectionZjoin_conditionsparamsqnZqn2indexZlhs_colZrhs_colZ extra_condZ extra_sqlZ extra_paramsZdeclared_fieldZ on_clause_sql alias_strZsqlrrr as_sql>s2   z Join.as_sqlcCs<|j|j|j}|j|j|j}|j|j|||j|j|jS)N)getrrr#rrrr)r change_mapZnew_parent_aliasZnew_table_aliasrrr relabeled_clonegs  zJoin.relabeled_clonecCs4t||jr0|j|jko.|j|jko.|j|jkSdS)NF) isinstancer#rrr)r otherrrr __eq__ns     z Join.__eq__cCs|ji}t|_|S)N)r.rr)r newrrr demotews z Join.demotecCs|ji}t|_|S)N)r.rr)r r2rrr promote|s z Join.promoteN) rrrrr r+r.r1r3r4rrrr rs) rc@s0eZdZdZdZdZddZddZddZdS) 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. NcCs||_||_dS)N)rr)r raliasrrr r szBaseTable.__init__cCs2|j|jkrdnd|j}|j|j}||gfS)Nrz %s)rrr)r r%r&r*Zbase_sqlrrr r+s zBaseTable.as_sqlcCs|j|j|j|j|jS)N)r#rr,r)r r-rrr r.szBaseTable.relabeled_clone) rrrrrrr r+r.rrrr r5s r5N) rZdjango.db.models.sql.constantsrr Exceptionrr objectrrr5rrrr s  f