"""
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 8.3.6
# EnterpriseDB 8.3
# PostgreSQL 8.3 beta4
# PostgreSQL 8.4beta1
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, 80304 for 8.3.4. The last two digits will be 00 in the case of
releases (e.g., 80400 for 'PostgreSQL 8.4') 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])