Sequelize：創建多個自我關聯

Question

我有 model “主題”，它與自己的“繼任者”和“前任者”有自我關系。 為此，我需要創建兩個外鍵“successorId”和“predecessorId”。

我能夠創建關系，但不知道如何在外鍵中添加條目。

Model 主題：

const { sequelize } = require('../config/databaseInit');
const { DataTypes, Model } = require('sequelize');

class Subject extends Model {}

Subject.init(
  {
    subjectCode: {
      type: DataTypes.STRING(40),
      unique: true,
    },
    subjectName: {
      type: DataTypes.STRING(60),
      allowNull: false,
    },
    ...
    ...
    ...
    successorId: {
      type: DataTypes.INTEGER,
      references: {
        model: 'Subject',
        key: 'id',
      },
    },
    predecessorId: {
      type: DataTypes.INTEGER,
      references: {
        model: 'Subject',
        key: 'id',
      },
    },
  },
  {
    sequelize: sequelize,
    modelName: 'Subject',
    tableName: 'Subject',
    timestamps: true,
  }
);

例如：

const sub1 = await Subject.create({....});
const sub2 = await Subject.create({....});

// None of them are working.
sub1.setSuccessorId(sub2);
sub1.setSuccessor(sub2);
sub1.update({ successorId: sub1.id });

Answer 1

您可以在此處確定您的關系 model 1-n/nn/1-n 鏈接： https://sequelize.org/master/manual/assocs.ZFC35FDC70D5FC69D269883A822C7A53

Subject.belongsTo(models.Class, { as: 'subject', foreignKey: 'subjectId' });