Fix get_table_names() reflection method

It did not respect the `schema` query argument in SQLAlchemy connection
URLs.

Author: amotl

CHANGES.md

@@ -6,6 +6,9 @@
 - Added support for CrateDB's [FLOAT_VECTOR] data type. For SQLAlchemy
   column definitions, you can use it like `FloatVector(dimensions=1024)`.
 
+- Fixed `get_table_names()` reflection method, it did not respect the
+  `schema` query argument in SQLAlchemy connection URLs.
+
 [FLOAT_VECTOR]: https://crate.io/docs/crate/reference/en/master/general/ddl/data-types.html#float-vector
 
 

src/sqlalchemy_cratedb/dialect.py

@@ -229,6 +229,15 @@ def connect(self, host=None, port=None, *args, **kwargs):
     def _get_default_schema_name(self, connection):
         return 'doc'
 
+    def _get_effective_schema_name(self, connection):
+        schema_name_raw = connection.engine.url.query.get("schema")
+        schema_name = None
+        if isinstance(schema_name_raw, str):
+            schema_name = schema_name_raw
+        elif isinstance(schema_name_raw, tuple):
+            schema_name = schema_name_raw[0]
+        return schema_name
+
     def _get_server_version_info(self, connection):
         return tuple(connection.connection.lowest_server_version.version)
 
@@ -258,6 +267,8 @@ def get_schema_names(self, connection, **kw):
 
     @reflection.cache
     def get_table_names(self, connection, schema=None, **kw):
+        if schema is None:
+            schema = self._get_effective_schema_name(connection)
         cursor = connection.exec_driver_sql(
             "SELECT table_name FROM information_schema.tables "
             "WHERE {0} = ? "