- implement postgres connection pool

- adapt current sqlalchemy based methods to produce raw sql

app/config.py

@@ -70,5 +70,29 @@ class Settings(BaseSettings):
             path=self.POSTGRES_DB,
         )
 
+    @computed_field
+    @property
+    def postgres_url(self) -> PostgresDsn:
+        """
+        This is a computed field that generates a PostgresDsn URL
+
+        The URL is built using the MultiHostUrl.build method, which takes the following parameters:
+        - scheme: The scheme of the URL. In this case, it is "postgres".
+        - username: The username for the Postgres database, retrieved from the POSTGRES_USER environment variable.
+        - password: The password for the Postgres database, retrieved from the POSTGRES_PASSWORD environment variable.
+        - host: The host of the Postgres database, retrieved from the POSTGRES_HOST environment variable.
+        - path: The path of the Postgres database, retrieved from the POSTGRES_DB environment variable.
+
+        Returns:
+            PostgresDsn: The constructed PostgresDsn URL.
+        """
+        return MultiHostUrl.build(
+            scheme="postgres",
+            username=self.POSTGRES_USER,
+            password=self.POSTGRES_PASSWORD,
+            host=self.POSTGRES_HOST,
+            path=self.POSTGRES_DB,
+        )
+
 
 settings = Settings()