add a lot of changes

backend/models/QuizSessionQuestion.js

@@ -0,0 +1,58 @@
+const { DataTypes } = require('sequelize');
+const { v4: uuidv4 } = require('uuid');
+
+module.exports = (sequelize) => {
+  const QuizSessionQuestion = sequelize.define('QuizSessionQuestion', {
+    id: {
+      type: DataTypes.CHAR(36),
+      primaryKey: true,
+      allowNull: false
+    },
+    quizSessionId: {
+      type: DataTypes.CHAR(36),
+      allowNull: false,
+      field: 'quiz_session_id'
+    },
+    questionId: {
+      type: DataTypes.CHAR(36),
+      allowNull: false,
+      field: 'question_id'
+    },
+    questionOrder: {
+      type: DataTypes.INTEGER.UNSIGNED,
+      allowNull: false,
+      field: 'question_order',
+      validate: {
+        min: 1
+      }
+    }
+  }, {
+    tableName: 'quiz_session_questions',
+    underscored: true,
+    timestamps: true,
+    createdAt: 'created_at',
+    updatedAt: 'updated_at',
+    hooks: {
+      beforeValidate: (quizSessionQuestion) => {
+        if (!quizSessionQuestion.id) {
+          quizSessionQuestion.id = uuidv4();
+        }
+      }
+    }
+  });
+
+  // Define associations
+  QuizSessionQuestion.associate = (models) => {
+    QuizSessionQuestion.belongsTo(models.QuizSession, {
+      foreignKey: 'quizSessionId',
+      as: 'quizSession'
+    });
+
+    QuizSessionQuestion.belongsTo(models.Question, {
+      foreignKey: 'questionId',
+      as: 'question'
+    });
+  };
+
+  return QuizSessionQuestion;
+};