fix(duckdb): correct configuration setup hook (#19)

DuckDB configurations were incorrectly setup. This change corrects the key value pair mapping.

Author: cofin

base.py

@@ -103,8 +103,8 @@ def _configure_connection(self, connection: "DuckDBPyConnection") -> None:
         Args:
             connection: The DuckDB connection to configure.
         """
-        for config in cast("list[str]", self.config):
-            connection.execute(config)
+        for key, value in cast("dict[str,Any]", self.config).items():
+            connection.execute(f"SET {key}='{value}'")
 
     def _configure_extensions(self, connection: "DuckDBPyConnection") -> None:
         """Configure extensions for the connection.

sqlspec/adapters/duckdb/config.py

@@ -35,6 +35,9 @@ def on_app_init(self, app_config: "AppConfig") -> "AppConfig":
 
         Args:
             app_config: The :class:`AppConfig <.config.app.AppConfig>` instance.
+
+        Returns:
+            The updated :class:`AppConfig <.config.app.AppConfig>` instance.
         """
 
         from sqlspec.base import ConfigManager