db seed command

api/target_exchange/__init__.py

@@ -1,3 +1,3 @@
 """exchange management"""
 
-from . import views
+from . import views, models

api/target_exchange/models.py

@@ -6,5 +6,7 @@ class TargetExchange(SurrogatePK, Model):
     __tablename__ = "target-exchange"
     name = Column(db.String(255), unique=True, nullable=False)
 
-    def __init__(self, name, **kwargs) -> None:
-        Model.__init__(self, name=name, **kwargs)
+    @staticmethod
+    def ensure_created(name):
+        if TargetExchange.query.filter_by(name=name).first() is None:
+            TargetExchange(name=name).save()