Asyncpg null query fix

Adjusted the asyncpg dialect so that an empty SQL string, which is valid
for PostgreSQL server, may be successfully processed at the dialect level,
such as when using :meth:`.Connection.exec_driver_sql`. Pull request
courtesy Andrew Jackson.

Closes: #12220
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/12220
Pull-request-sha: 45c94febee66b567040b1fbfa3a93079a1314f09

Change-Id: I870df9e31f4a229939e76c702724c25073329282
(cherry picked from commit 7bfb829f25c1bfe2139afe7875882298aaf345ba)

diff --git a/doc/build/changelog/unreleased_20/12220.rst b/doc/build/changelog/unreleased_20/12220.rst
new file mode 100644 (file)
index 0000000..a4b30cc
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/12220.rst
@@ -0,0 +1,9 @@
+.. change::
+    :tags: bug, postgresql
+    :tickets: 12220
+
+    Adjusted the asyncpg dialect so that an empty SQL string, which is valid
+    for PostgreSQL server, may be successfully processed at the dialect level,
+    such as when using :meth:`.Connection.exec_driver_sql`. Pull request
+    courtesy Andrew Jackson.
+

diff --git a/lib/sqlalchemy/dialects/postgresql/asyncpg.py b/lib/sqlalchemy/dialects/postgresql/asyncpg.py
index 1761c8de53cb1d46966de45e13b796299099b853..523c47abcd0116f5b7b193052ac262987eb1cc72 100644 (file)
--- a/lib/sqlalchemy/dialects/postgresql/asyncpg.py
+++ b/lib/sqlalchemy/dialects/postgresql/asyncpg.py
@@ -546,7 +546,8 @@ class AsyncAdapt_asyncpg_cursor:
                     status = prepared_stmt.get_statusmsg()
 
                     reg = re.match(
-                        r"(?:SELECT|UPDATE|DELETE|INSERT \d+) (\d+)", status
+                        r"(?:SELECT|UPDATE|DELETE|INSERT \d+) (\d+)",
+                        status or "",
                     )
                     if reg:
                         self.rowcount = int(reg.group(1))

diff --git a/test/dialect/postgresql/test_dialect.py b/test/dialect/postgresql/test_dialect.py
index 892e2abc9be02a450c954ae5bca7700389b73996..109101011fc865f1885583ca04e7713242a11df5 100644 (file)
--- a/test/dialect/postgresql/test_dialect.py
+++ b/test/dialect/postgresql/test_dialect.py
@@ -1040,6 +1040,12 @@ class MiscBackendTest(
     __only_on__ = "postgresql"
     __backend__ = True
 
+    @testing.fails_on(["+psycopg2"])
+    def test_empty_sql_string(self, connection):
+
+        result = connection.exec_driver_sql("")
+        assert result._soft_closed
+
     @testing.provide_metadata
     def test_date_reflection(self):
         metadata = self.metadata