I don't think you'll be able to get what you want in an onupdate function. You'd probably be better off with the before_insert and before_update mapper events:
https://docs.sqlalchemy.org/en/14/orm/events.html#sqlalchemy.orm.MapperEvents.before_insert https://docs.sqlalchemy.org/en/14/orm/events.html#sqlalchemy.orm.MapperEvents.before_update Hope that helps, Simon On Sun, Jun 20, 2021 at 5:37 PM peizhi qin <aodong...@gmail.com> wrote: > > I have a table ,the definition is as follows: > class TEnterprise(Base): > __tablename__ = 't_enterprise' > __table_args__ = ( > {'mysql_engine': 'InnoDB', 'mysql_charset': 'latin1'} > ) > > Fent_id = Column(String(32), primary_key=True) > Fent_type = Column(INTEGER(11), nullable=False) > Fcomb_cert_state = Column(INTEGER(11), nullable=False) > Fstate = Column(INTEGER(11), nullable=False) > Fbusiness_license_copy = Column(String(256), nullable=False) > Fbusiness_license_number = Column(String(32), nullable=False) > Fmerchant_name = Column(String(128), nullable=False) > Fsign = Column(String(64), nullable=False, server_default=text("''")) > > the Fsign=md5(Fcomb_cert_state=${Fcomb_cert_state}&Fent_id=${Fent_id}) > > i can use context.current_parameters get the value of the field to be > updated, but how to get the value of the field that has not been updated, > thanks for help! > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/sqlalchemy/bc9a6c71-90dd-4c7a-a5a8-9712f43d24f6n%40googlegroups.com. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/CAFHwexfwaB5PUdvYj9sGukhtM36iWTc%2B41pG1vMdmV5dYLuVJA%40mail.gmail.com.