In the onupdate function, how to get the value of the row of records to be updated

[peizhi qin]

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!

[Simon King]

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

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[peizhi qin]

before_ insert before_ update can solve my problem. Thank you very much