From a1de76c42f6b64808448aed6e821fbb3b988f99b Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 12 Dec 2016 12:07:11 -0500 Subject: [PATCH] - xmin example requires a server default declaration to function correctly Change-Id: I1cc50da6fe1c0eeef1d00201b45d998daddfd8ac --- doc/build/orm/versioning.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/doc/build/orm/versioning.rst b/doc/build/orm/versioning.rst index a2f1635c90..563185604d 100644 --- a/doc/build/orm/versioning.rst +++ b/doc/build/orm/versioning.rst @@ -142,12 +142,14 @@ which provides UPDATE versioning. We can make use of the PostgreSQL ``xmin`` column to version our ``User`` class as follows:: + from sqlalchemy import FetchedValue + class User(Base): __tablename__ = 'user' id = Column(Integer, primary_key=True) name = Column(String(50), nullable=False) - xmin = Column("xmin", Integer, system=True) + xmin = Column("xmin", Integer, system=True, server_default=FetchedValue()) __mapper_args__ = { 'version_id_col': xmin, -- 2.47.2