如何使用 Flask SQLAlchemy 中第 4 个表中的键查询 4 ​​个表？

Question

I have four tables with the structure as below:

class Vendors(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    companyName = db.Column(db.String(100))
    billingAddress = db.Column(db.String(100))
    shippingAddress = db.Column(db.String(100))
    contactPersonName = db.Column(db.String(100))
    contactPersonNumber = db.Column(db.String(100))
    gstNo = db.Column(db.String(100))
    openingBalance = db.Column(db.BIGINT)
    creditPeriod = db.Column(db.String(100))
    vendorCode = db.Column(db.String(100))
    vendorProducts = db.relationship('VendorsProduct', backref="vendProd")

class VendorsProduct(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    bf = db.Column(db.Integer)
    gsm = db.Column(db.Integer)
    types = db.Column(db.String(100))
    itemCode = db.Column(db.String(100))
    vendorID = db.Column(db.String(100), db.ForeignKey('vendors.vendorCode'))
    vendorInwards = db.relationship('VendorsInward', backref="vendInward")


class VendorsInward(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    reel = db.Column(db.String(100))
    deckle = db.Column(db.Integer)
    weight = db.Column(db.Integer)
    vendorInwardID = db.Column(
        db.String(100), db.ForeignKey('vendors_product.itemCode'))
    reelID = db.relationship('ReelStatusTable', backref="reelStatusTable")


class ReelStatusTable(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    reelStatus = db.Column(db.String(100))
    reelCode = db.Column(db.String(100), db.ForeignKey('vendors_inward.reel'))

In the ReelStatusTable under the reelStatus I have values named In Stock . I want to query in Flask-SQLAlchemy all the In Stock entries associated with a Vendors table.

I tried the following code and it simply displays all the values from the reelStatus and I cannot only query the In Stock ones :(

vendorsProductsList = db.session.query(
        Vendors
    ).join(
        VendorsProduct
    ).join(
        VendorsInward
    ).join(
        ReelStatusTable
    ).filter(
        ReelStatusTable.reelStatus == "In Stock"
    ).all()

Please help me query the In Stock entries.

NOTE: I want to use Vendors.name , VendorsProduct.bf , VendorsProduct.gsm , VendorsProduct.types , VendorsInward.reel, VendorsInward.deckle, VendorsInward.weight and ReelStatusTable.reelStatus fields in my flask application

Thank you in Advance.

Answer 1

It worked after I tried this query !!

vendorsProductsList = db.session.query(Vendors,
                                           VendorsProduct,
                                           VendorsInward,
                                           ReelStatusTable
                                           ).filter(
                                               ReelStatusTable.reelStatus == "In Stock"
                                               ).filter(
                                                   ReelStatusTable.reelCode == VendorsInward.reel
                                                   ).filter(
                                                       VendorsInward.vendorInwardID == VendorsProduct.itemCode
                                                       ).filter(
                                                           VendorsProduct.vendorID == Vendors.vendorCode
                                                           ).all()