From f4e4ae96cb69d616af6f7009512cdcd2cb7c1e39 Mon Sep 17 00:00:00 2001
From: Adrian Holovaty <adrian@holovaty.com>
Date: Tue, 2 Aug 2005 22:33:39 +0000
Subject: Improved 'django-admin inspectdb' so that it detects ForeignKey
 relationships -- PostgreSQL only

git-svn-id: http://code.djangoproject.com/svn/django/trunk@395 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/core/db/__init__.py            |  1 +
 django/core/db/backends/mysql.py      |  3 +++
 django/core/db/backends/postgresql.py | 21 +++++++++++++++++++++
 django/core/db/backends/sqlite3.py    |  3 +++
 4 files changed, 28 insertions(+)

(limited to 'django/core/db')

diff --git a/django/core/db/__init__.py b/django/core/db/__init__.py
index 4ecf33770c..43ca2b2619 100644
--- a/django/core/db/__init__.py
+++ b/django/core/db/__init__.py
@@ -38,6 +38,7 @@ get_last_insert_id = dbmod.get_last_insert_id
 get_date_extract_sql = dbmod.get_date_extract_sql
 get_date_trunc_sql = dbmod.get_date_trunc_sql
 get_table_list = dbmod.get_table_list
+get_relations = dbmod.get_relations
 OPERATOR_MAPPING = dbmod.OPERATOR_MAPPING
 DATA_TYPES = dbmod.DATA_TYPES
 DATA_TYPES_REVERSE = dbmod.DATA_TYPES_REVERSE
diff --git a/django/core/db/backends/mysql.py b/django/core/db/backends/mysql.py
index aa99516209..886a0a38b8 100644
--- a/django/core/db/backends/mysql.py
+++ b/django/core/db/backends/mysql.py
@@ -73,6 +73,9 @@ def get_table_list(cursor):
     cursor.execute("SHOW TABLES")
     return [row[0] for row in cursor.fetchall()]
 
+def get_relations(cursor, table_name):
+    raise NotImplementedError
+
 OPERATOR_MAPPING = {
     'exact': '=',
     'iexact': 'LIKE',
diff --git a/django/core/db/backends/postgresql.py b/django/core/db/backends/postgresql.py
index cd8d9a064e..94a6ed35c3 100644
--- a/django/core/db/backends/postgresql.py
+++ b/django/core/db/backends/postgresql.py
@@ -82,6 +82,27 @@ def get_table_list(cursor):
             AND pg_catalog.pg_table_is_visible(c.oid)""")
     return [row[0] for row in cursor.fetchall()]
 
+def get_relations(cursor, table_name):
+    """
+    Returns a dictionary of {field_index: (field_index_other_table, other_table)}
+    representing all relationships to the given table. Indexes are 0-based.
+    """
+    cursor.execute("""
+        SELECT con.conkey, con.confkey, c2.relname
+        FROM pg_constraint con, pg_class c1, pg_class c2
+        WHERE c1.oid = con.conrelid
+            AND c2.oid = con.confrelid
+            AND c1.relname = %s
+            AND con.contype = 'f'""", [table_name])
+    relations = {}
+    for row in cursor.fetchall():
+        try:
+            # row[0] and row[1] are like "{2}", so strip the curly braces.
+            relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2])
+        except ValueError:
+            continue
+    return relations
+
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
 # use mx.DateTime by default.
diff --git a/django/core/db/backends/sqlite3.py b/django/core/db/backends/sqlite3.py
index b719b8f8cd..38ce767dfb 100644
--- a/django/core/db/backends/sqlite3.py
+++ b/django/core/db/backends/sqlite3.py
@@ -112,6 +112,9 @@ def _sqlite_date_trunc(lookup_type, dt):
 def get_table_list(cursor):
     raise NotImplementedError
 
+def get_relations(cursor, table_name):
+    raise NotImplementedError
+
 # Operators and fields ########################################################
 
 OPERATOR_MAPPING = {
-- 
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