add error code 1049 for mysql has_table

Fixed regression caused by issue :ticket:`9058` which adjusted the MySQL
dialect's ``has_table()`` to again use "DESCRIBE", where the specific error
code raised by MySQL version 8 when using a non-existent schema name was
unexpected and failed to be interpreted as a boolean result.

Fixed the SQLite dialect's ``has_table()`` function to correctly report
False for queries that include a non-None schema name for a schema that
doesn't exist; previously, a database error was raised.

Fixes: #9251
Change-Id: I5ef9cf0887865c3c521d88bca0ba18954a108241

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/suite/test_reflection.py b/lib/sqlalchemy/testing/suite/test_reflection.py
index 2550eff4e..8b7cb8cbc 100644
--- a/lib/sqlalchemy/testing/suite/test_reflection.py
+++ b/lib/sqlalchemy/testing/suite/test_reflection.py
@@ -177,6 +177,15 @@ class HasTableTest(OneConnectionTablesTest):
                 )
             )
 
+    @testing.requires.schemas
+    def test_has_table_nonexistent_schema(self):
+        with config.db.begin() as conn:
+            is_false(
+                config.db.dialect.has_table(
+                    conn, "test_table", schema="nonexistent_schema"
+                )
+            )
+
     @testing.requires.views
     def test_has_table_view(self, connection):
         insp = inspect(connection)