diff --git a/accountant/api/models/accounts.py b/accountant/api/models/accounts.py
index 1bb7d6c..0255b8d 100644
--- a/accountant/api/models/accounts.py
+++ b/accountant/api/models/accounts.py
@@ -44,3 +44,7 @@ class Account(db.Model):
         ).outerjoin(Entry).group_by(cls.id).order_by(cls.id)
 
         return query
+
+    @classmethod
+    def get(cls, session, id):
+        return session.query(cls).filter(cls.id == id).one()
diff --git a/accountant/api/models/entries.py b/accountant/api/models/entries.py
index df64e8d..cd8e052 100644
--- a/accountant/api/models/entries.py
+++ b/accountant/api/models/entries.py
@@ -62,3 +62,7 @@ class Entry(db.Model):
         ).filter(cls.account_id == account_id).order_by("year", "month")
 
         return query
+
+    @classmethod
+    def get(cls, session, id):
+        return session.query(cls).filter(cls.id == id).one()
diff --git a/accountant/api/models/operations.py b/accountant/api/models/operations.py
index 3b212fd..0fe296b 100644
--- a/accountant/api/models/operations.py
+++ b/accountant/api/models/operations.py
@@ -95,3 +95,7 @@ class Operation(db.Model):
         ).group_by(cls.account_id)
 
         return query
+
+    @classmethod
+    def get(cls, session, id):
+        return session.query(cls).filter(cls.id == id).one()
diff --git a/accountant/api/models/scheduled_operations.py b/accountant/api/models/scheduled_operations.py
index 4eaad97..f8a2a51 100644
--- a/accountant/api/models/scheduled_operations.py
+++ b/accountant/api/models/scheduled_operations.py
@@ -67,3 +67,7 @@ class ScheduledOperation(db.Model):
         )
 
         return query
+
+    @classmethod
+    def get(cls, session, id):
+        return session.query(cls).filter(cls.id == id).one()