Given the following declarative schema, how can I generate the UPDATE
statement? I am using MySQL
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
str = Column(String(16), nullable=False)
bs = relationship(B)
class B(Base):
__tablename__ = 'b'
id = Column(Integer, primary_key=True)
a_id = Column(Integer, ForeignKey(A.id), nullable=False)
typ = Column(Enum('1', '2'), nullable=False)
str = Column(String(16), nullable=False)
__table_args__ = ( UniqueConstraint(a_id, typ), )
UPDATE a
INNER JOIN b ON b.a_id = a.id
SET a.str = CONCAT(a.str, b.str)
WHERE b.typ = '2';
I have tried
session.query(A).join(B).filter(B.typ == '2').update({ 'str':
func.concat(A.str, B.str) }, synchonize_session=False)
but this raises an exception
s.execute(update(A).join(B, b.a_id == A.id).where(B.typ ==
'2').values(str=func.concat(A.str, B.str)))
does not work because join is not a member of Update
How can I achieve this? It would be especially nice if I could use the
session to do so rather than raw sql expression
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
---
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sqlalchemy+unsubscr...@googlegroups.com.
To post to this group, send email to sqlalchemy@googlegroups.com.
Visit this group at https://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
