Fixed #25175 -- Renamed the postgresql_psycopg2 database backend to postgresql.

1 files changed, 44 insertions, 0 deletions

diff --git a/django/db/backends/postgresql/version.py b/django/db/backends/postgresql/version.py
new file mode 100644
index 0000000000..d558fb2e51
--- /dev/null
+++ b/django/db/backends/postgresql/version.py
@@ -0,0 +1,44 @@
+"""
+Extracts the version of the PostgreSQL server.
+"""
+
+import re
+
+# This reg-exp is intentionally fairly flexible here.
+# Needs to be able to handle stuff like:
+#   PostgreSQL #.#.#
+#   EnterpriseDB #.#
+#   PostgreSQL #.# beta#
+#   PostgreSQL #.#beta#
+VERSION_RE = re.compile(r'\S+ (\d+)\.(\d+)\.?(\d+)?')
+
+
+def _parse_version(text):
+    "Internal parsing method. Factored out for testing purposes."
+    major, major2, minor = VERSION_RE.search(text).groups()
+    try:
+        return int(major) * 10000 + int(major2) * 100 + int(minor)
+    except (ValueError, TypeError):
+        return int(major) * 10000 + int(major2) * 100
+
+
+def get_version(connection):
+    """
+    Returns an integer representing the major, minor and revision number of the
+    server. Format is the one used for the return value of libpq
+    PQServerVersion()/``server_version`` connection attribute (available in
+    newer psycopg2 versions.)
+
+    For example, 90304 for 9.3.4. The last two digits will be 00 in the case of
+    releases (e.g., 90400 for 'PostgreSQL 9.4') or in the case of beta and
+    prereleases (e.g. 90100 for 'PostgreSQL 9.1beta2').
+
+    PQServerVersion()/``server_version`` doesn't execute a query so try that
+    first, then fallback to a ``SELECT version()`` query.
+    """
+    if hasattr(connection, 'server_version'):
+        return connection.server_version
+    else:
+        with connection.cursor() as cursor:
+            cursor.execute("SELECT version()")
+            return _parse_version(cursor.fetchone()[0])