Simplified get_key_columns()/get_relations() introspection methods for PostgreSQL.

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Mariusz Felisiak 2019-07-20 15:15:41 +02:00 committed by GitHub
parent 9f11939dd1
commit 842fd620ff
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1 changed files with 4 additions and 17 deletions

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@ -115,8 +115,11 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
Return a dictionary of {field_name: (field_name_other_table, other_table)}
representing all relationships to the given table.
"""
return {row[0]: (row[2], row[1]) for row in self.get_key_columns(cursor, table_name)}
def get_key_columns(self, cursor, table_name):
cursor.execute("""
SELECT c2.relname, a1.attname, a2.attname
SELECT a1.attname, c2.relname, a2.attname
FROM pg_constraint con
LEFT JOIN pg_class c1 ON con.conrelid = c1.oid
LEFT JOIN pg_class c2 ON con.confrelid = c2.oid
@ -124,22 +127,6 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
LEFT JOIN pg_attribute a2 ON c2.oid = a2.attrelid AND a2.attnum = con.confkey[1]
WHERE c1.relname = %s AND con.contype = 'f'
""", [table_name])
return {row[1]: (row[2], row[0]) for row in cursor.fetchall()}
def get_key_columns(self, cursor, table_name):
cursor.execute("""
SELECT kcu.column_name, ccu.table_name AS referenced_table, ccu.column_name AS referenced_column
FROM information_schema.constraint_column_usage ccu
LEFT JOIN information_schema.key_column_usage kcu
ON ccu.constraint_catalog = kcu.constraint_catalog
AND ccu.constraint_schema = kcu.constraint_schema
AND ccu.constraint_name = kcu.constraint_name
LEFT JOIN information_schema.table_constraints tc
ON ccu.constraint_catalog = tc.constraint_catalog
AND ccu.constraint_schema = tc.constraint_schema
AND ccu.constraint_name = tc.constraint_name
WHERE kcu.table_name = %s AND tc.constraint_type = 'FOREIGN KEY'
""", [table_name])
return cursor.fetchall()
def get_constraints(self, cursor, table_name):