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[英]How can I query a particular ID with sequelize.js so I can update it
[英]How can I parse complex query operations using Sequelize.js?
我有一個Option
表,它有一個question_id
作為表Questions
的外鍵。 然后在Questions
表中,我有 2 個外鍵,即question_category_id
和section_id
。 對於第一個選項部分,我可以應用LEFT OUTER JOIN
查詢,但我還需要獲取Question_Category
和Section
表的值。 讓我先弄清楚我希望我的輸出是怎樣的:
輸出 JSON
"questions": [
{
"id": 9,
"isActive": true,
"question_text": "What is abc ?",
"createdBy": "avis",
"questionCategory": {
"id": 1,
"name": "aptitude"
},
"section": {
"id": 1,
"marks": 5
},
"options": [
{
"id": 1,
"answer": true,
"option_text": "A",
"question_id": 9
},
{
"id": 2,
"answer": false,
"option_text": "B",
"question_id": 9
}
]
}
]
現在我指定我的數據庫模型:
question_category.js
module.exports = (sequelize, Sequelize) => {
const QuestionCategory = sequelize.define('question_category', {
id:{ type: Sequelize.BIGINT, autoIncrement: true, allowNull: false, primaryKey: true },
isActive: { type: Sequelize.BOOLEAN, allowNull: false },
question_category_name: { type: Sequelize.STRING, allowNull: false },
createdBy: { type: Sequelize.STRING, allowNull: false },
createdAt: { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.literal('CURRENT_TIMESTAMP') }
}, { timestamps: false });
return QuestionCategory;
};
節.js
module.exports = (sequelize, Sequelize) => {
const Section = sequelize.define('section', {
id: { type: Sequelize.BIGINT, autoIncrement: true, allowNull: false, primaryKey: true },
isActive: { type: Sequelize.BOOLEAN, allowNull: false },
marks_per_question: { type: Sequelize.INTEGER, allowNull: false },
createdBy: { type: Sequelize.STRING, allowNull: false },
createdAt: { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.literal('CURRENT_TIMESTAMP') }
}, { timestamps: false });
return Section;
};
問題.js
module.exports = (sequelize, Sequelize) => {
const Questions = sequelize.define('questions', {
id:{ type: Sequelize.BIGINT, autoIncrement: true, allowNull: false, primaryKey: true },
isActive: { type: Sequelize.BOOLEAN, allowNull: false },
question_text: { type: Sequelize.STRING, allowNull: false },
createdBy: { type: Sequelize.STRING, allowNull: false },
createdAt: { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.literal('CURRENT_TIMESTAMP') }
}, { timestamps: false });
return Questions;
};
選項.js
module.exports = (sequelize, Sequelize) => {
const Options = sequelize.define('options', {
id:{ type: Sequelize.BIGINT, autoIncrement: true, allowNull: false, primaryKey: true },
answer: { type: Sequelize.BOOLEAN, allowNull: true },
option_text: { type: Sequelize.STRING, allowNull: false },
createdAt: { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.literal('CURRENT_TIMESTAMP') }
}, { timestamps: false });
return Options;
};
在database.js 中,即用於導出模型的主 js 文件,我將模型關聯如下:
const dbConfig = require('../config/db.config');
const Sequelize = require('sequelize');
const sequelize = new Sequelize(
dbConfig.DB, dbConfig.USER, dbConfig.PASSWORD,
{
host: dbConfig.HOST,
port: dbConfig.PORT,
dialect: 'mysql',
operatorsAliases: 0
}
);
sequelize.authenticate().then(() => {
console.log('Connection has been established successfully.');
}).catch(err => {
console.error('Unable to connect to the database:', err);
});
const db = {};
db.Sequelize = Sequelize;
db.sequelize = sequelize;
db.QuestionCategory = require('./question_model/question_category')(sequelize, Sequelize);
db.Section = require('./question_model/section')(sequelize, Sequelize);
db.Question = require('./question_model/question')(sequelize, Sequelize);
db.Option = require('./question_model/option')(sequelize, Sequelize);
// Relating Question Category with Questions
db.QuestionCategory.hasMany(db.Question, {
foreignKey: 'question_category_id',
sourceKey: 'id'
});
db.Question.belongsTo(db.QuestionCategory, {
foreignKey: 'question_category_id',
targetKey: 'id'
});
// Relating Sections with Questions
db.Section.hasMany(db.Question, {
foreignKey: 'section_id',
sourceKey: 'id'
});
db.Question.belongsTo(db.Section, {
foreignKey: 'section_id',
targetKey: 'id'
});
// Relating Questions with Options
db.Question.hasMany(db.Option, {
foreignKey: 'question_id',
sourceKey: 'id'
});
db.Option.belongsTo(db.Question, {
foreignKey: 'question_id',
targetKey: 'id'
});
所以這是我的結構。 現在為了實現上述輸出格式,我編寫了以下邏輯,但它沒有輸出正確的 JSON:
const db = require('../models/database');
const errors = require('../config/errors').errors;
exports.viewQuestion = (req, res, next) => {
try {
db.Question.findAll({
attributes: { exclude: ['createdAt','section_id','question_category_id'] },
include: [{
model: db.Option,
attributes: { exclude: ['createdAt'] }
}]
}).then(data => {
if(data.length == 0) {
return res.status(200).send({
status: 200,
questions: 'No Data'
});
}
db.QuestionCategory.findAll({
attributes: { exclude: ['createdBy','createdAt','isActive'] },
include: db.Question,
attributes: { exclude: ['id','isActive','question_text','createdBy','createdAt','section_id'] }
}).then(question_category => {
Object.assign(data[0], { 'questionCategories': question_category });
res.status(200).send({
status: 200,
questions: data
});
});
}).catch(err => {
return res.status(204).send(errors.MANDATORY_FIELDS);
});
} catch(err) {
return res.status(204).send(errors.MANDATORY_FIELDS);
}
};
我還沒有為Section
部分編寫邏輯,因為我正在逐步進行。 我通過編寫這個邏輯得到的輸出是:
{
"status": 200,
"questions": [
{
"id": 9,
"isActive": true,
"question_text": "What is abc ?",
"createdBy": "avis",
"options": [
{
"id": 1,
"answer": true,
"option_text": "A",
"question_id": 9
},
{
"id": 2,
"answer": false,
"option_text": "B",
"question_id": 9
}
]
}
]
}
questionCategories
沒有反映在輸出中。
請幫助我,因為我有更多這樣的場景,我可以根據這個解決所有問題。
如果您使用 Sequelize 通過模型從數據庫獲取對象,那么您應該在添加一些屬性之前將它們轉換為普通對象。 例如,如果您獲得一組對象,您應該為每個對象調用get({ plain: true })
。
const plainObj = data[0].get({ plain: true })
Object.assign(plainObj, { 'questionCategories': question_category });
res.status(200).send({
status: 200,
questions: plainObj
});
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