Sequelize增删改查与事务 | Sequelize

本文转载自查看原文 2022-02-22 21:48 674 Node.js

Sequelize ORM

1.数据的增删改查与事务

初始化模型

const { Sequelize, Model, DataTypes } = require("sequelize");


const sequelize = new Sequelize({
    dialect: "mysql",
    host: "localhost",
    port: 3306,
    username: "root",
    password: "password",
    database: "demo",
    timezone: "+08:00",
    pool: {
        max: 10,
        min: 0
    },
    logging: true,
});


class User extends Model {}

User.init({
    id: {
        type: DataTypes.INTEGER({ unsigned: true }),
        primaryKey: true,
        autoIncrement: true,
        comment: "用户ID",
    },
    username: {
        type: DataTypes.STRING(40),
        unique: true,
        allowNull: false,
        comment: "账号",
    },
    password: {
        type: DataTypes.CHAR(64),
        allowNull: false,
        comment: "密码",
    },
}, {
    sequelize: sequelize,
    tableName: "user",
    modelName: "user",
    paranoid: true,  // 逻辑删除，填充删除时间
    underscored: true,  // 内置字段用下划线代替驼峰命名
});

增

单条插入

(async ()=>{
    try{
        await sequelize.sync({force: true});
        const user = await User.create({
            username: "mkl",
            password: "123456",
        });
        console.log("创建成功", user.toJSON());
    } catch(e){
        console.log(e);
    }
})();

批量插入

(async ()=>{
    try{
        await sequelize.sync({force: true});
        const users = await User.bulkCreate([
            {username: "mkl", password: "123456"}, 
            {username: "bob", password: "123456"},
        ], {
            individualHooks: true, // 对每个数据都执行一次生命周期，为false只执行bulkCreate的生命周期
        });
        console.log("创建成功", users.map(user=>user.toJSON()));
    } catch(e){
        console.log(e);
    }
})();

更新

批量更新

(async ()=>{
    try{
        // await sequelize.sync({force: true});
        const [count, users] = await User.update({username: "bob", password: "123456"},
        {
            where: {
                username: 'marry',
            },
            individualHooks: true, // 对每个数据都执行一次生命周期，为false只执行bulkCreate的生命周期
        });
        console.log(`总共更新了${count}`, users.map(user=>user.toJSON()));
    } catch(e){
        console.log(e);
    }
})();

单条更新

(async ()=>{
    try{
        const user = await User.findOne({
            where: {
                username: "bob"
            }
        });
        if (!user){
            throw new Error("用户不存在.");
        }
        user.password = "password";
        await user.save();
        console.log(user.toJSON());
    } catch(e){
        console.log(e);
    }
})();

删除

批量删除(逻辑)

(async ()=>{
    try{
        const count = await User.destroy({
            where: {
                username: "bob"
            }
        });
        console.log(`删除了${count}条数据.`)
    } catch(e){
        console.log(e);
    }
})();

单条删除(物理)

查询

单条查询

根据ID查询

(async ()=>{
    /**
    * 根据ID查询
    */
    const userById = await User.findByPk(1);
    console.log(userById?userById.toJSON():"未查到数据");
})();

findOne根据where查询

(async ()=>{
    /**
    * 根据条件查询，并返回指定字段
    */
    const user = await User.findOne({
        attributes: ["password"],
        where: {
            username: "mkl",
        }
    });
    console.log(user?user.toJSON():"未查到数据");
})();

多条查询

(async ()=>{
    /**
    * 根据条件查询，并返回指定字段
    */
    const user = await User.findAll({
        attributes: ["password"],
        where: {
            username: "mkl",
        },
        order: [
            ["id", "DESC"],
            ["username", "DESC"],
        ],
        offset: 0,
        limit: 10
    });
    console.log(user);
})();

查询或创建单条数据

(async ()=>{
    /**
    * 根据条件查询，并返回指定字段
    */
    const [user, created] = await User.findOrCreate({
        where: {
            username: "bob",
        },
        defaults: {
            username: "bob",
            password: "password",
        }
    });
    if (created){
        console.log("创建用户成功", user.toJSON());
    } else {
        console.log("查询用户成功", user.toJSON());
    }
    console.log(user);
})();

同时查询列表和数据总数

(async ()=>{
    const {rows, count} = await User.findAndCountAll({
        where: {
            username: "mkl",
        }
    });
    console.log(rows.map(row=>row.toJSON()), count);
})();

统计数据

(async () => {
    const count = await User.count({
        where: {
            username: "mkl",
        }
    });
    console.log(count);
})();

事务

自动事务

(async () => {
    const result = await sequelize.transaction({
        isolationLevel: Transaction.ISOLATION_LEVELS.SERIALIZABLE  // 设置隔离级别
    }, async (transaction) => {
        const user = await User.create({
            username: "marry",
            password: 123,
        }, {transaction: transaction});  // 选项中必须传递事务对象
        const user2 = await User.create({
            username: "jerry",
            password: 456,
        }, {transaction: transaction});
        return [user, user2];
    });
    console.log(result.map(user=>user.toJSON()));
})();

手动事务

(async () => {
    const transaction = await sequelize.transaction({
        isolationLevel: Transaction.ISOLATION_LEVELS.SERIALIZABLE,
    });
    try{
        const user = await User.create({
            username: "miaokela",
            password: "password",
        }, {transaction: transaction});
        const user2 = await User.create({
            username: "boby",
            password: "123456",
        });
        await transaction.commit();
    } catch(e){
        await transaction.rollback();
        throw e;
    }
})();

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