From f87f9c5f63f779edc74f286ccf88d13db96c44de Mon Sep 17 00:00:00 2001
From: Nick Pope <nick.pope@flightdataservices.com>
Date: Wed, 12 Sep 2018 01:18:16 +0100
Subject: [PATCH] Simplified introspection methods for PostgreSQL.
---
.../db/backends/postgresql/introspection.py | 37 +++++++++----------
1 file changed, 18 insertions(+), 19 deletions(-)
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
index 584a2e86b6..afd035df77 100644
--- a/django/db/backends/postgresql/introspection.py
+++ b/django/db/backends/postgresql/introspection.py
@@ -46,10 +46,13 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r', 'v')
AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
- AND pg_catalog.pg_table_is_visible(c.oid)""")
- return [TableInfo(row[0], {'r': 't', 'v': 'v'}.get(row[1]))
- for row in cursor.fetchall()
- if row[0] not in self.ignored_tables]
+ AND pg_catalog.pg_table_is_visible(c.oid)
+ """)
+ mapping = {'r': 't', 'v': 'v'}
+ return [
+ TableInfo(row[0], mapping[row[1]])
+ for row in cursor.fetchall() if row[0] not in self.ignored_tables
+ ]
def get_table_description(self, cursor, table_name):
"""
@@ -70,12 +73,11 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
]
def get_sequences(self, cursor, table_name, table_fields=()):
- sequences = []
cursor.execute("""
SELECT s.relname as sequence_name, col.attname
FROM pg_class s
JOIN pg_namespace sn ON sn.oid = s.relnamespace
- JOIN pg_depend d ON d.refobjid = s.oid AND d.refclassid='pg_class'::regclass
+ JOIN pg_depend d ON d.refobjid = s.oid AND d.refclassid = 'pg_class'::regclass
JOIN pg_attrdef ad ON ad.oid = d.objid AND d.classid = 'pg_attrdef'::regclass
JOIN pg_attribute col ON col.attrelid = ad.adrelid AND col.attnum = ad.adnum
JOIN pg_class tbl ON tbl.oid = ad.adrelid
@@ -85,9 +87,10 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
AND n.nspname = 'public'
AND tbl.relname = %s
""", [table_name])
- for row in cursor.fetchall():
- sequences.append({'name': row[0], 'table': table_name, 'column': row[1]})
- return sequences
+ return [
+ {'name': row[0], 'table': table_name, 'column': row[1]}
+ for row in cursor.fetchall()
+ ]
def get_relations(self, cursor, table_name):
"""
@@ -101,15 +104,11 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
LEFT JOIN pg_class c2 ON con.confrelid = c2.oid
LEFT JOIN pg_attribute a1 ON c1.oid = a1.attrelid AND a1.attnum = con.conkey[1]
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])
- relations = {}
- for row in cursor.fetchall():
- relations[row[1]] = (row[2], row[0])
- return relations
+ 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):
- key_columns = []
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
@@ -121,9 +120,9 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
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])
- key_columns.extend(cursor.fetchall())
- return key_columns
+ WHERE kcu.table_name = %s AND tc.constraint_type = 'FOREIGN KEY'
+ """, [table_name])
+ return cursor.fetchall()
def get_constraints(self, cursor, table_name):
"""