add a lot of changes

backend/models/QuizAnswer.js

@@ -0,0 +1,134 @@
+const { v4: uuidv4 } = require('uuid');
+
+module.exports = (sequelize, DataTypes) => {
+  const QuizAnswer = sequelize.define('QuizAnswer', {
+    id: {
+      type: DataTypes.CHAR(36),
+      primaryKey: true,
+      defaultValue: () => uuidv4(),
+      allowNull: false,
+      comment: 'UUID primary key'
+    },
+    quizSessionId: {
+      type: DataTypes.CHAR(36),
+      allowNull: false,
+      field: 'quiz_session_id',
+      validate: {
+        notEmpty: {
+          msg: 'Quiz session ID is required'
+        },
+        isUUID: {
+          args: 4,
+          msg: 'Quiz session ID must be a valid UUID'
+        }
+      },
+      comment: 'Foreign key to quiz_sessions table'
+    },
+    questionId: {
+      type: DataTypes.CHAR(36),
+      allowNull: false,
+      field: 'question_id',
+      validate: {
+        notEmpty: {
+          msg: 'Question ID is required'
+        },
+        isUUID: {
+          args: 4,
+          msg: 'Question ID must be a valid UUID'
+        }
+      },
+      comment: 'Foreign key to questions table'
+    },
+    selectedOption: {
+      type: DataTypes.STRING(255),
+      allowNull: false,
+      field: 'selected_option',
+      validate: {
+        notEmpty: {
+          msg: 'Selected option is required'
+        }
+      },
+      comment: 'The option selected by the user'
+    },
+    isCorrect: {
+      type: DataTypes.BOOLEAN,
+      allowNull: false,
+      field: 'is_correct',
+      comment: 'Whether the selected answer was correct'
+    },
+    pointsEarned: {
+      type: DataTypes.INTEGER.UNSIGNED,
+      allowNull: false,
+      defaultValue: 0,
+      field: 'points_earned',
+      validate: {
+        min: {
+          args: [0],
+          msg: 'Points earned must be non-negative'
+        }
+      },
+      comment: 'Points earned for this answer'
+    },
+    timeTaken: {
+      type: DataTypes.INTEGER.UNSIGNED,
+      allowNull: false,
+      defaultValue: 0,
+      field: 'time_taken',
+      validate: {
+        min: {
+          args: [0],
+          msg: 'Time taken must be non-negative'
+        }
+      },
+      comment: 'Time taken to answer in seconds'
+    },
+    answeredAt: {
+      type: DataTypes.DATE,
+      allowNull: false,
+      defaultValue: DataTypes.NOW,
+      field: 'answered_at',
+      comment: 'When the question was answered'
+    }
+  }, {
+    tableName: 'quiz_answers',
+    timestamps: true,
+    underscored: true,
+    indexes: [
+      {
+        fields: ['quiz_session_id'],
+        name: 'idx_quiz_answers_session_id'
+      },
+      {
+        fields: ['question_id'],
+        name: 'idx_quiz_answers_question_id'
+      },
+      {
+        fields: ['quiz_session_id', 'question_id'],
+        unique: true,
+        name: 'idx_quiz_answers_session_question_unique'
+      },
+      {
+        fields: ['is_correct'],
+        name: 'idx_quiz_answers_is_correct'
+      },
+      {
+        fields: ['answered_at'],
+        name: 'idx_quiz_answers_answered_at'
+      }
+    ]
+  });
+
+  // Associations
+  QuizAnswer.associate = (models) => {
+    QuizAnswer.belongsTo(models.QuizSession, {
+      foreignKey: 'quizSessionId',
+      as: 'quizSession'
+    });
+    QuizAnswer.belongsTo(models.Question, {
+      foreignKey: 'questionId',
+      as: 'question'
+    });
+  };
+
+  return QuizAnswer;
+};

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;
+};