Refactor DBHandler to support dialect-specific required fields and update example config for SQLite

Author: mgv99

besser/agent/db/db_handler.py

@@ -20,7 +20,11 @@ class DBHandler:
     configuration and opens connections lazily when they are first needed.
     """
 
-    _REQUIRED_DB_FIELDS = {'dialect', 'host', 'port', 'database', 'username', 'password'}
+    _DEFAULT_REQUIRED_DB_FIELDS = {'dialect', 'host', 'port', 'database', 'username', 'password'}
+    _DIALECT_REQUIRED_DB_FIELDS = {
+        'sqlite': {'dialect', 'file'},
+        'postgres': {'dialect', 'host', 'port', 'database', 'username', 'password'}
+    }
     _SQL_COMMAND_PATTERN = re.compile(r'^\s*(?:/\*.*?\*/\s*|--.*?(?:\n|\r\n?)\s*)*([a-zA-Z]+)', re.DOTALL)
 
     def __init__(self, agent: 'Agent'):
@@ -50,24 +54,36 @@ def _extract_db_configs(self, config: dict[str, Any]) -> dict[str, dict[str, Any
         return db_configs
 
     def _validate_db_config(self, db_name: str, db_config: dict[str, Any]) -> bool:
-        missing = sorted(field for field in self._REQUIRED_DB_FIELDS if db_config.get(field) is None)
+        required_fields = self._required_db_fields(db_config)
+        missing = sorted(field for field in required_fields if db_config.get(field) is None)
         if missing:
+            dialect = db_config.get('dialect')
             logger.error(
-                "Missing required DB properties for '%s': %s. Expected under 'db.sql.%s'.",
+                "Missing required DB properties for '%s' (dialect=%s): %s. Expected under 'db.sql.%s'. Required fields: %s.",
                 db_name,
+                dialect,
                 ', '.join(missing),
                 db_name,
+                ', '.join(sorted(required_fields)),
             )
             return False
         return True
 
+    def _required_db_fields(self, db_config: dict[str, Any]) -> set[str]:
+        dialect = db_config.get('dialect')
+        if dialect is None:
+            return {'dialect'}
+
+        dialect_name = str(dialect).split('+', 1)[0].lower()
+        return self._DIALECT_REQUIRED_DB_FIELDS.get(dialect_name, self._DEFAULT_REQUIRED_DB_FIELDS)
+
     def _build_db_url(self, db_name: str) -> URL | str | None:
         try:
             db_config = self._db_configs[db_name]
             dialect = str(db_config['dialect'])
 
             if dialect.startswith('sqlite'):
-                return URL.create(drivername=dialect, database=str(db_config['database']))
+                return URL.create(drivername=dialect, database=str(db_config['file']))
 
             return URL.create(
                 drivername=dialect,

besser/agent/test/examples/config.yaml

@@ -60,12 +60,8 @@ db:
     password: YOUR-DB-PASSWORD
   sql:
     - db1:
-        dialect: postgresql
-        host: YOUR-DB-HOST
-        port: 5432
-        database: YOUR-DB-NAME
-        username: YOUR-DB-USERNAME
-        password: YOUR-DB-PASSWORD
+      dialect: sqlite
+      database: path/to/local.db
     - db2:
         dialect: postgresql
         host: YOUR-DB-HOST

docs/source/wiki/db/db_handler.rst

@@ -35,12 +35,8 @@ You can define multiple DBs in configuration:
             username: user
             password: pass
         - db2:
-            dialect: postgresql
-            host: localhost
-            port: 5432
-            database: analytics_db
-            username: user
-            password: pass
+            dialect: sqlite
+            file: path/to/local_database.db
 
 Query a DB in a State Body
 --------------------------