feat(core): AWEL flow 2.0 backend code (#1879)

Co-authored-by: yhjun1026 <460342015@qq.com>

dbgpt/serve/flow/models/variables_adapter.py

@@ -0,0 +1,71 @@
+from typing import Type
+
+from sqlalchemy.orm import Session
+
+from dbgpt.core.interface.storage import StorageItemAdapter
+from dbgpt.core.interface.variables import StorageVariables, VariablesIdentifier
+
+from .models import VariablesEntity
+
+
+class VariablesAdapter(StorageItemAdapter[StorageVariables, VariablesEntity]):
+    """Variables adapter.
+
+    Convert between storage format and database model.
+    """
+
+    def to_storage_format(self, item: StorageVariables) -> VariablesEntity:
+        """Convert to storage format."""
+        return VariablesEntity(
+            key=item.key,
+            name=item.name,
+            label=item.label,
+            value=item.value,
+            value_type=item.value_type,
+            category=item.category,
+            encryption_method=item.encryption_method,
+            salt=item.salt,
+            scope=item.scope,
+            scope_key=item.scope_key,
+            sys_code=item.sys_code,
+            user_name=item.user_name,
+            description=item.description,
+        )
+
+    def from_storage_format(self, model: VariablesEntity) -> StorageVariables:
+        """Convert from storage format."""
+        return StorageVariables(
+            key=model.key,
+            name=model.name,
+            label=model.label,
+            value=model.value,
+            value_type=model.value_type,
+            category=model.category,
+            encryption_method=model.encryption_method,
+            salt=model.salt,
+            scope=model.scope,
+            scope_key=model.scope_key,
+            sys_code=model.sys_code,
+            user_name=model.user_name,
+            description=model.description,
+        )
+
+    def get_query_for_identifier(
+        self,
+        storage_format: Type[VariablesEntity],
+        resource_id: VariablesIdentifier,
+        **kwargs,
+    ):
+        """Get query for identifier."""
+        session: Session = kwargs.get("session")
+        if session is None:
+            raise Exception("session is None")
+        query_obj = session.query(VariablesEntity)
+        for key, value in resource_id.to_dict().items():
+            if value is None:
+                continue
+            query_obj = query_obj.filter(getattr(VariablesEntity, key) == value)
+
+        # enabled must be True
+        query_obj = query_obj.filter(VariablesEntity.enabled == 1)
+        return query_obj