How would you make a hybrid_property
that allows the in_
clause? What would the SQLAlchemy expression
look like?
class Version(Base):
version_id = Column(Integer, primary_key=True)
package_id = Column(Integer, ForeignKey('package.package_id')
version = Column(String(32), index=True)
@hybrid_property
def pkg_id_concat_vers(self):
# "23~~0.2.4"
return "{}~~{}".format(self.package_id, self.version)
# TODO
#@pkg_id_concat_vers(self):
# pass
# Using the naive `(not) in` doesn't actually apply the filter
data = ['23~~0.2.4', '57~~0.0.1']
result = (session.query(Version)
.filter(Version.pkg_id_concat_vers in data)
).all()
# Using `in_()` throws an Attribute Error, as it's a string.
data = ['23~~0.2.4', '57~~0.0.1']
result = (session.query(Version)
.filter(Version.pkg_id_concat_vers.in_(data))
).all()
SQLAlchemy supports the +
operator on expressions with type String
, so you can cast your columns to String
and then do something like this:
@pkg_id_concat_vers.expression
def pkg_id_concat_vers(cls):
return cast(cls.package_id, String) + "~~" + cast(cls.version, String)
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.