Merge pull request #1112 from dbcli/j-bennet/pqconninfo-1110

[WIP] Fix for PQconninfo not available.

changelog.rst

@@ -11,12 +11,13 @@ Features:
 Bug fixes:
 ----------
 
-* Error connecting to PostgreSQL 12beta1 (#1058). (Thanks: `Irina Truong`_)
+* Error connecting to PostgreSQL 12beta1 (#1058). (Thanks: `Irina Truong`_ and `Amjith Ramanujam`_)
 * Empty query caused error message (#1019) (Thanks: `Sebastian Janko`_)
 * History navigation bindings in multiline queries (#1004) (Thanks: `Pedro Ferrari`_)
 * Can't connect to pgbouncer database (#1093). (Thanks: `Irina Truong`_)
 * Fix broken multi-line history search (#1031). (Thanks: `Owen Stephens`_)
 * Fix slow typing/movement when multi-line query ends in a semicolon (#994). (Thanks: `Owen Stephens`_)
+* Fix for PQconninfo not available in libpq < 9.3 (#1110). (Thanks: `Irina Truong`_)
 
 Internal:
 ---------

pgcli/pgexecute.py

@@ -265,14 +265,32 @@ class PGExecute(object):
         # When we connect using a DSN, we don't really know what db,
         # user, etc. we connected to. Let's read it.
         # Note: moved this after setting autocommit because of #664.
-        # TODO: use actual connection info from psycopg2.extensions.Connection.info as psycopg>2.8 is available and required dependency  # noqa
-        dsn_parameters = conn.get_dsn_parameters()
+        libpq_version = psycopg2.__libpq_version__
+        dsn_parameters = {}
+        if libpq_version >= 93000:
+            # use actual connection info from psycopg2.extensions.Connection.info
+            # as libpq_version > 9.3 is available and required dependency
+            dsn_parameters = conn.info.dsn_parameters
+        else:
+            try:
+                dsn_parameters = conn.get_dsn_parameters()
+            except Exception as x:
+                # https://github.com/dbcli/pgcli/issues/1110
+                # PQconninfo not available in libpq < 9.3
+                _logger.info("Exception in get_dsn_parameters: %r", x)
+
+        if dsn_parameters:
+            self.dbname = dsn_parameters.get("dbname")
+            self.user = dsn_parameters.get("user")
+            self.host = dsn_parameters.get("host")
+            self.port = dsn_parameters.get("port")
+        else:
+            self.dbname = conn_params.get("database")
+            self.user = conn_params.get("user")
+            self.host = conn_params.get("host")
+            self.port = conn_params.get("port")
 
-        self.dbname = dsn_parameters.get("dbname")
-        self.user = dsn_parameters.get("user")
         self.password = password
-        self.host = dsn_parameters.get("host")
-        self.port = dsn_parameters.get("port")
         self.extra_args = kwargs
 
         if not self.host:

setup.py

@@ -17,7 +17,7 @@ install_requirements = [
     "click >= 4.1",
     "Pygments >= 2.0",  # Pygments has to be Capitalcased. WTF?
     "prompt_toolkit>=2.0.6,<2.1.0",
-    "psycopg2 >= 2.7.4",
+    "psycopg2 >= 2.8",
     "sqlparse >=0.3.0,<0.4",
     "configobj >= 5.0.6",
     "humanize >= 0.5.1",