>
>
> class FinishedGoodsChild(TimestampMixin, db.Model):
>
> id = db.Column(db.Integer, primary_key=True)
>
> hold_qty = db.Column(db.Float, default=0)
> pen_qty = db.Column(db.Float, default=0)
> qty = db.Column(db.Float, nullable=False, default=0)
> sku = db.Column(db.String(40), nullable=False, default='')
> size = db.relationship('SizeMaster',
> secondary='size_goods_child', passive_deletes=
> True, backref='size_goods_child', lazy='joined')
>
> size_id = db.Column(db.Integer, nullable=False, default=None)
>
> def __init__(self, qty, sku, size):
> self.qty = qty
> self.sku = sku
> self.size_id = size.id
> self.size.append(size)
>
>
> db.Table('size_goods_child',
>
> db.Column('size_id', db.Integer, db.ForeignKey(
> 'size_master.id', ), primary_key=True, nullable=False
> ),
> db.Column('goods_id', db.Integer, db.ForeignKey(
> 'finished_goods_child.id', ), primary_key=True, nullable=
> False
> )
> )
>
>
> class FinishedGoodsChildSchema(ma.ModelSchema):
> id = field_for(FinishedGoodsChild, 'id', dump_only=True)
> qty = field_for(FinishedGoodsChild, 'qty', dump_only=True)
> hold_qty = field_for(FinishedGoodsChild, 'hold_qty', dump_only=True)
> pen_qty = field_for(FinishedGoodsChild, 'pen_qty', dump_only=True)
> sku = field_for(FinishedGoodsChild, 'sku', dump_only=True)
>
> size = ma.Nested(SizeMasterSchema, many=True)
>
> class meta:
> model = FinishedGoodsChild
>
>
> db.Table('hsn_goods',
> db.Column('hsn_id', db.Integer, db.ForeignKey(
> 'hsn.id', ), primary_key=True, nullable=False
> ),
> db.Column('goods_id', db.Integer, db.ForeignKey(
> 'finished_goods.id', ), primary_key=True, nullable=False
> )
> )
>
> class FinishedGoods(SearchableMixin, TimestampMixin, db.Model):
> __searchable__ = ['balance','created', 'updated', 'title',
> 'description', 'sku','qty',
> 'product_category', 'fabric_combination',
> 'print_technique', 'design_number']
>
> id = db.Column(db.Integer, primary_key=True)
>
> filter_tags = db.relationship(
> 'FilterTags', passive_deletes=True, secondary='filter_tags_goods'
> , backref='filter_tags_goods', lazy='joined')
> product_category = db.relationship(
> 'ProductCategory', passive_deletes=True, secondary=
> 'product_category_goods', backref='product_category_goods', lazy='joined')
> fabric_combination = db.relationship(
> 'FabricCombination', passive_deletes=True, secondary=
> 'fabric_combination_goods', backref='fabric_combination_goods', lazy=
> 'joined')
> print_technique = db.relationship(
> 'PrintTechnique', passive_deletes=True, secondary=
> 'print_technique_goods', backref='print_technique_goods', lazy='joined')
> design_number = db.relationship(
> 'DesignNumber', passive_deletes=True, secondary=
> 'design_number_goods', backref='design_number_goods', lazy='joined')
> uom = db.relationship('Uom',
> secondary='uom_goods', passive_deletes=True,
> backref='uom_goods', lazy='joined')
> hsn = db.relationship('Hsn',
> secondary='hsn_goods', passive_deletes=True,
> backref='hsn_goods', lazy='joined')
> size = db.relationship('SizeMaster',
> secondary='size_goods', passive_deletes=True,
> backref='size_goods', lazy='joined')
>
> size_chart = db.relationship('SizeChart',
> secondary='size_chart_goods',
> passive_deletes=True, backref='size_chart_goods', lazy='joined')
>
> # Foreign Key IDs for Unique Constraint
>
> product_category_id = db.Column(db.Integer, nullable=False)
> fabric_combination_id = db.Column(db.Integer, nullable=False)
> print_technique_id = db.Column(db.Integer, nullable=False)
> design_number_id = db.Column(db.Integer, nullable=False)
> uom_id = db.Column(db.Integer, nullable=False)
> size_id = db.Column(db.Integer, nullable=False, default=None)
> # End FK
> title = db.Column(db.String(100), nullable=False)
> description = db.Column(db.String(250), nullable=False)
>
> price = db.Column(db.Float, nullable=False, default="0")
> qty = db.Column(db.Float, nullable=False)
> hold_qty = db.Column(db.Float, default=0)
> pen_qty = db.Column(db.Float, default=0)
>
> gst = db.Column(db.Integer, nullable=False, default="0")
> multiple = db.Column(db.Integer, nullable=False, default=1)
> sku = db.Column(db.String(40), nullable=False)
>
> image = db.Column(db.String(250))
>
> children = db.relationship('FinishedGoodsChild',
> passive_deletes=True, secondary=
> 'goods_child_sizes', backref='goods_child_sizes', lazy='joined')
> balance = db.Column(db.Float , default= 0)
>
> __table_args__ = (db.UniqueConstraint(
> 'product_category_id', 'fabric_combination_id',
> 'print_technique_id', 'design_number_id', 'sku', name=
> 'finished_goods_chk_id'), )
>
> def __init__(self, product_category, fabric_combination,
> print_technique, design_number, uom, size, title, description, sku, price
> , qty, multiple):
> self.product_category_id = product_category.id
> self.product_category.append(product_category)
>
> self.fabric_combination_id = fabric_combination.id
> self.fabric_combination.append(fabric_combination)
>
> self.print_technique_id = print_technique.id
> self.print_technique.append(print_technique)
>
> self.design_number_id = design_number.id
> self.design_number.append(design_number)
>
> self.uom_id = uom.id
> self.uom.append(uom)
>
> self.size_id = size.id
> self.size.append(size)
>
> self.title = title
> self.description = description
> self.price = price
> self.qty = qty
> self.multiple = multiple
> self.sku = sku
>
> def get_gen_name(self):
> goods_name = "{}/{}/{}/{}".format(
> self.product_category[0].name, self.fabric_combination[0
> ].name, self.print_technique[0].name, self.design_number[0].name)
> return goods_name
>
On Thu, Oct 22, 2020 at 3:53 PM Simon King <si...@simonking.org.uk> wrote:
> You don't need to add a parent_id column, you just need to write the
> full relationship condition inside that "select" statement. It would
> be much easier to explain if you can show your actual parent and child
> classes, including the relationship between them and the association
> table.
>
> Simon
>
> On Thu, Oct 22, 2020 at 7:23 AM Padam Sethia <padamseth...@gmail.com>
> wrote:
> >
> > Thanks for your input , the children have a many to many relationship
> with the parent FinishedGoods , with this how would I refer to parent_id ,
> do i need to create and add that also ?
> >
> > On Wed, 21 Oct 2020, 14:48 Simon King, <si...@simonking.org.uk> wrote:
> >>
> >> The "expression" part of a hybrid property is used whenever you write
> >> "FinishedGoodsParent.balance". It operates in the context of the
> >> class, not a single instance, and it needs to return an SQL expression
> >> that can be used inside a larger query.
> >>
> >> In your version, you are trying to iterate over "cls.children", but
> >> that's not possible because "cls.children" is not a list. Hybrid
> >> properties that work across relationships can be a bit difficult to
> >> think about. The expression that you return needs to access another
> >> table, so you need to consider how the query will join to that table:
> >>
> >>
> https://docs.sqlalchemy.org/en/13/orm/extensions/hybrid.html#working-with-relationships
> >>
> >> In your case, you actually need to perform an aggregating function
> >> (sum) on the related table. The easiest way to do that would be to
> >> follow the correlated subquery example from the docs:
> >>
> >>
> https://docs.sqlalchemy.org/en/13/orm/extensions/hybrid.html#correlated-subquery-relationship-hybrid
> >>
> >> Something like this:
> >>
> >> @balance.expression
> >> def balance(cls):
> >> return select([sa.func.sum(FinishedGoodsChild.qty)]).\
> >> where(FinishedGoodsChild.parent_id==cls.id).\
> >> label('balance')
> >>
> >> You probably need something a bit more complicated than that - I
> >> didn't understand the join condition between parent and child in your
> >> example so I made up the "parent_id" column.
> >>
> >> Hope that helps,
> >>
> >> Simon
> >>
> >> On Tue, Oct 20, 2020 at 4:57 PM Padam Sethia <padamseth...@gmail.com>
> wrote:
> >> >
> >> > Hello ,
> >> >
> >> > I'm having an issue with Hybrid methods - I still don't understand
> them enough properly . So I have a parent and child many to many
> relationship
> >> >
> >> >
> >> > This is the child model
> >> >
> >> > class FinishedGoodsChild(TimestampMixin, db.Model):
> >> > id = db.Column(db.Integer, primary_key=True)
> >> > hold_qty = db.Column(db.Float, default=0)
> >> > pen_qty = db.Column(db.Float, default=0)
> >> > qty = db.Column(db.Float, nullable=False, default=0)
> >> > sku = db.Column(db.String(40), nullable=False, default='')
> >> > size = db.relationship('SizeMaster',
> secondary='size_goods_child', passive_deletes=True,
> backref='size_goods_child', lazy='joined')
> >> > size_id = db.Column(db.Integer, nullable=False, default=None)
> >> >
> >> > This is the Parent model
> >> >
> >> >
> >> > class FinishedGoodsChild(TimestampMixin, db.Model):
> >> > id = db.Column(db.Integer, primary_key=True)
> >> > qty = db.Column(db.Float, default=0)
> >> > balance = db.Column(db.Float)
> >> > children = db.relationship('FinishedGoodsChild',
> passive_deletes=True, secondary='goods_child_sizes',
> backref='goods_child_sizes', lazy='joined')
> >> >
> >> >
> >> > No I need to filter by the sum of the children qty
> >> >
> >> >
> >> > Here is the hybrid property that I have set up , but throws not
> implemented error
> >> >
> >> >
> >> > @hybrid_property
> >> > def balance(self):
> >> > return sum(acc.qty for acc in self.children) @balance.expression
> >> > def balance(cls):
> >> > return sum(acc.qty for acc in cls.children)
> >> >
> >> > Help is much appreciated thanks!
> >> >
> >> > --
> >> > 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.
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> https://groups.google.com/d/msgid/sqlalchemy/ba1add47-9497-4b92-8cb8-926e03c958a5n%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
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> .
> >
> > --
> > 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.
> > ---
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> .
>
> --
> 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.
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>
--
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.
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