1 files changed, 85 insertions, 0 deletions
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
new file mode 100644
index 0000000000..c4f759da10
--- /dev/null
+++ b/django/db/backends/postgresql/introspection.py
@@ -0,0 +1,85 @@
+from django.db import transaction
+from django.db.backends.postgresql.base import quote_name
+
+def get_table_list(cursor):
+    "Returns a list of table names in the current database."
+    cursor.execute("""
+        SELECT c.relname
+        FROM pg_catalog.pg_class c
+        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 [row[0] for row in cursor.fetchall()]
+
+def get_table_description(cursor, table_name):
+    "Returns a description of the table, with the DB-API cursor.description interface."
+    cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name))
+    return cursor.description
+
+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
+
+def get_indexes(cursor, table_name):
+    """
+    Returns a dictionary of fieldname -> infodict for the given table,
+    where each infodict is in the format:
+        {'primary_key': boolean representing whether it's the primary key,
+         'unique': boolean representing whether it's a unique index}
+    """
+    # Get the table description because we only have the column indexes, and we
+    # need the column names.
+    desc = get_table_description(cursor, table_name)
+    # This query retrieves each index on the given table.
+    cursor.execute("""
+        SELECT idx.indkey, idx.indisunique, idx.indisprimary
+        FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
+            pg_catalog.pg_index idx
+        WHERE c.oid = idx.indrelid
+            AND idx.indexrelid = c2.oid
+            AND c.relname = %s""", [table_name])
+    indexes = {}
+    for row in cursor.fetchall():
+        # row[0] (idx.indkey) is stored in the DB as an array. It comes out as
+        # a string of space-separated integers. This designates the field
+        # indexes (1-based) of the fields that have indexes on the table.
+        # Here, we skip any indexes across multiple fields.
+        if ' ' in row[0]:
+            continue
+        col_name = desc[int(row[0])-1][0]
+        indexes[col_name] = {'primary_key': row[2], 'unique': row[1]}
+    return indexes
+
+# Maps type codes to Django Field types.
+DATA_TYPES_REVERSE = {
+    16: 'BooleanField',
+    21: 'SmallIntegerField',
+    23: 'IntegerField',
+    25: 'TextField',
+    869: 'IPAddressField',
+    1043: 'CharField',
+    1082: 'DateField',
+    1083: 'TimeField',
+    1114: 'DateTimeField',
+    1184: 'DateTimeField',
+    1266: 'TimeField',
+    1700: 'FloatField',
+}