鏈接一個Sequelize模型到兩個不同的領域，從另一個模型

Question

我有兩個型號：

• BusinessEntity和
• Invoice

我想Invoice有一個seller和buyer，兩者都指向BusinessEntity記錄。所以，我希望在invoices表（Invoice型號）有兩個字段：seller_id和buyer_id。

所以，我做了這樣的事情：

BusinessEntity

const BusinessEntity = sequelize.define("business_entity", { 
    display_name: Sequelize.STRING 
}); 

Invoice

const Invoice = sequelize.define("invoice", { 
    series: Sequelize.STRING, 
    number: Sequelize.INTEGER, 
    ... 
}); 

// Indeed, this creates the seller_id and buyer_id fields in the invoice 
Invoice.belongsTo(BusinessEntity, { as: "seller" }); 
Invoice.belongsTo(BusinessEntity, { as: "buyer" }); 

似乎不自然的我打電話給Invoice.belongsTo(BusinessEntity)，但如果我這樣做：

BusinessEntity.belongsTo(Invoice, { as: "seller" }); 
BusinessEntity.belongsTo(Invoice, { as: "buyer" }); 

... seller_id和buyer_id列根本不創建。爲什麼？

---

我成功插入的發票，從business_entities表assiging IDS。

我該如何查詢Invoice當我想includeseller和buyer在輸出？

我想：

Invoice.findOne({ include: [BusinessEntity] }) 

但是失敗，此錯誤：

business_entity is not associated to invoice! 

什麼是做到這一點的正確方法？如何解決問題？

Answer 1

當您執行findOne查詢時：Invoice.findOne({ include: [BusinessEntity] })還必須提及別名。

所以，你需要查詢的格式如下：