1.EggJS引用Sequelize
- 安装sequelize依赖和mysql驱动
cnpm i egg-sequelize mysql2 -S
- 启用sequelize插件
在config/plugin.js里面添加
sequelize: {
enable: true,
package: 'egg-sequelize',
},
- 配置数据库
在config/config.default.js里面添加
config.sequelize = {
dialect: 'mysql', // 表示使用mysql
host: '127.0.0.1', // 连接的数据库主机地址
port: 3306, // mysql服务端口
database: 'demo', // 数据库名
username: 'root', // 数据库用户名
password: 'root', // 数据库密码
define: { // model的全局配置
timestamps: true, // 添加create,update,delete时间戳
paranoid: true, // 添加软删除
freezeTableName: true, // 防止修改表名为复数
underscored: false // 防止驼峰式字段被默认转为下划线
},
timezone: '+8:00', // 由于orm用的UTC时间，这里必须加上东八区，否则取出来的时间相差8小时
dialectOptions: { // 让读取date类型数据时返回字符串而不是UTC时间
dateStrings: true,
typeCast(field, next) {
if (field.type === "DATETIME") {
return field.string();
}
return next();
}
}
};
2.定义Model
- 刚开始使用egg-init构建的Egg项目是没有app/model目录的，初始的项目结构如下:
itzishu
├── README.md
├── app
│ ├── controller
│ │ └── home.js
│ └── router.js
├── appveyor.yml
├── config
│ ├── config.default.js
│ └── plugin.js
├── package.json
└── test
└── app
└── controller
└── home.test.js
先在app目录下新建一个目录为model，里面用来存放所有的数据库里面定义的表的实例对象内容。
- 数据库表的内容如下：
/*
Navicat Premium Data Transfer
Source Server : 系统数据库3306
Source Server Type : MySQL
Source Server Version : 50725
Source Host : localhost:3306
Source Schema : demo
Target Server Type : MySQL
Target Server Version : 50725
File Encoding : 65001
Date: 12/05/2019 15:11:37
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for classes
-- ----------------------------
DROP TABLE IF EXISTS `classes`;
CREATE TABLE `classes` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`createdAt` datetime DEFAULT NULL,
`updatedAt` datetime DEFAULT NULL,
`deletedAt` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of classes
-- ----------------------------
BEGIN;
INSERT INTO `classes` VALUES (1, '软件工程1601', '2019-05-12 13:11:43', '2019-05-12 13:11:47', NULL);
INSERT INTO `classes` VALUES (2, '网络工程1601', '2019-05-12 13:12:10', '2019-05-12 13:12:13', NULL);
COMMIT;
-- ----------------------------
-- Table structure for info
-- ----------------------------
DROP TABLE IF EXISTS `info`;
CREATE TABLE `info` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`age` int(11) NOT NULL,
`sex` tinyint(255) NOT NULL DEFAULT '1' COMMENT '1为男，0为女',
`studentId` int(11) NOT NULL,
`createdAt` datetime DEFAULT NULL,
`updatedAt` datetime DEFAULT NULL,
`deletedAt` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of info
-- ----------------------------
BEGIN;
INSERT INTO `info` VALUES (1, '许仙', 23, 1, 1, '2019-05-12 13:25:58', '2019-05-12 13:26:01', NULL);
INSERT INTO `info` VALUES (2, '白素贞', 20, 0, 2, '2019-05-12 13:26:41', '2019-05-12 13:26:46', NULL);
INSERT INTO `info` VALUES (3, '法海', 22, 1, 3, '2019-05-12 13:27:20', '2019-05-12 13:27:22', NULL);
INSERT INTO `info` VALUES (4, '小青', 18, 0, 4, '2019-05-12 13:27:48', '2019-05-12 13:27:51', NULL);
INSERT INTO `info` VALUES (5, '金如意', 20, 0, 5, '2019-05-12 13:28:34', '2019-05-12 13:28:37', NULL);
INSERT INTO `info` VALUES (6, '景松', 23, 1, 6, '2019-05-12 13:30:07', '2019-05-12 13:30:10', NULL);
COMMIT;
-- ----------------------------
-- Table structure for lession
-- ----------------------------
DROP TABLE IF EXISTS `lession`;
CREATE TABLE `lession` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`createdAt` datetime DEFAULT NULL,
`updatedAt` datetime DEFAULT NULL,
`deletedAt` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of lession
-- ----------------------------
BEGIN;
INSERT INTO `lession` VALUES (1, '计算机网络', '2019-05-12 13:12:32', '2019-05-12 13:12:35', NULL);
INSERT INTO `lession` VALUES (2, 'Java程序设计', '2019-05-12 13:12:50', '2019-05-12 13:12:52', NULL);
INSERT INTO `lession` VALUES (3, '软件项目管理', '2019-05-12 13:13:07', '2019-05-12 13:13:10', NULL);
INSERT INTO `lession` VALUES (4, '网络安全', '2019-05-12 13:13:22', '2019-05-12 13:13:25', NULL);
COMMIT;
-- ----------------------------
-- Table structure for lession_student
-- ----------------------------
DROP TABLE IF EXISTS `lession_student`;
CREATE TABLE `lession_student` (
`lessionId` int(11) NOT NULL,
`studentId` int(11) NOT NULL,
`createdAt` datetime DEFAULT NULL,
`updatedAt` datetime DEFAULT NULL,
`deletedAt` datetime DEFAULT NULL,
PRIMARY KEY (`lessionId`,`studentId`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of lession_student
-- ----------------------------
BEGIN;
INSERT INTO `lession_student` VALUES (1, 1, '2019-05-12 13:20:35', '2019-05-12 13:20:40', NULL);
INSERT INTO `lession_student` VALUES (1, 2, '2019-05-12 13:20:51', '2019-05-12 13:20:53', NULL);
INSERT INTO `lession_student` VALUES (1, 3, '2019-05-12 13:21:02', '2019-05-12 13:21:05', NULL);
INSERT INTO `lession_student` VALUES (1, 4, '2019-05-12 13:21:15', '2019-05-12 13:21:19', NULL);
INSERT INTO `lession_student` VALUES (1, 5, '2019-05-12 13:21:29', '2019-05-12 13:21:32', NULL);
INSERT INTO `lession_student` VALUES (1, 6, '2019-05-12 13:21:43', '2019-05-12 13:21:45', NULL);
INSERT INTO `lession_student` VALUES (2, 1, '2019-05-12 13:23:10', '2019-05-12 13:23:13', NULL);
INSERT INTO `lession_student` VALUES (2, 3, '2019-05-12 13:23:28', '2019-05-12 13:23:31', NULL);
INSERT INTO `lession_student` VALUES (2, 4, '2019-05-12 13:23:40', '2019-05-12 13:23:43', NULL);
INSERT INTO `lession_student` VALUES (2, 5, '2019-05-12 13:23:54', '2019-05-12 13:23:57', NULL);
INSERT INTO `lession_student` VALUES (3, 1, '2019-05-12 13:24:21', '2019-05-12 13:24:24', NULL);
INSERT INTO `lession_student` VALUES (3, 4, '2019-05-12 13:24:39', '2019-05-12 13:24:42', NULL);
INSERT INTO `lession_student` VALUES (4, 2, '2019-05-12 13:24:59', '2019-05-12 13:25:03', NULL);
INSERT INTO `lession_student` VALUES (4, 6, '2019-05-12 13:25:12', '2019-05-12 13:25:15', NULL);
COMMIT;
-- ----------------------------
-- Table structure for student
-- ----------------------------
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`number` varchar(12) NOT NULL COMMENT '学号',
`password` varchar(32) NOT NULL,
`classId` int(11) NOT NULL,
`createdAt` datetime DEFAULT NULL,
`updatedAt` datetime DEFAULT NULL,
`deletedAt` datetime DEFAULT NULL,
PRIMARY KEY (`id`,`number`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8mb4;
-- ----------------------------
-- Records of student
-- ----------------------------
BEGIN;
INSERT INTO `student` VALUES (1, '160101', '202cb962ac59075b964b07152d234b70', 1, '2019-05-12 13:16:09', '2019-05-12 13:16:12', NULL);
INSERT INTO `student` VALUES (2, '160201', '202cb962ac59075b964b07152d234b70', 2, '2019-05-12 13:16:32', '2019-05-12 13:16:35', NULL);
INSERT INTO `student` VALUES (3, '160102', '202cb962ac59075b964b07152d234b70', 1, '2019-05-12 13:17:17', '2019-05-12 13:17:21', NULL);
INSERT INTO `student` VALUES (4, '160103', '202cb962ac59075b964b07152d234b70', 1, '2019-05-12 13:17:51', '2019-05-12 13:17:54', NULL);
INSERT INTO `student` VALUES (5, '160104', '202cb962ac59075b964b07152d234b70', 1, '2019-05-12 13:18:13', '2019-05-12 13:18:16', NULL);
INSERT INTO `student` VALUES (6, '160202', '202cb962ac59075b964b07152d234b70', 2, '2019-05-12 13:18:36', '2019-05-12 13:18:39', NULL);
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
其中，各个表之间存在联系为：
- student与info存在一对一关系
- classes与student存在一对多关系
- student与lession存在多对多关系，中间表为lession_student
-
根据数据表的结构，我们确定关系并写好model目录下相关文件
- student.js
module.exports = app => {
const { STRING, INTEGER } = app.Sequelize;
const Student = app.model.define('student', {
id: {
type: INTEGER,
autoIncrement: true,
primaryKey: true
},
number: {
type: STRING,
allowNull: false,
},
password: {
type: STRING(32),
allowNull: false
},
classId: {
type: INTEGER,
allowNull: false
}
});
Student.associate = function (){
// 与Info存在一对多关系，所以是hasOne()
app.model.Student.hasOne(app.model.Info, {foreignKey: 'studentId'});
// 与Classes存在多对一关系，所以使用belongsTo()
app.model.Student.belongsTo(app.model.Classes, {foreignKey: 'classId', targetKey: 'id'});
// 与Lessison存在多对多关系，使用belongsToMany()
app.model.Student.belongsToMany(app.model.Lession, {
through: app.model.LessionStudent,
foreignKey: 'studentId',
otherKey: 'lessionId'
});
}
return Student;
}
- info.js
module.exports = app => {
const { STRING, INTEGER, BOOLEAN } = app.Sequelize;
const Info = app.model.define('info', {
id: {
type: INTEGER,
autoIncrement: true,
primaryKey: true
},
name: {
type: STRING(50),
allowNull: false,
},
age: {
type: INTEGER,
allowNull: false
},
sex: {
type: BOOLEAN,
allowNull: false,
get() {
if ( this.getDataValue('sex') ){
return '男';
}else {
return '女';
}
}
},
studentId: {
type: INTEGER,
allowNull: false
}
});
Info.associate = function (){
app.model.Info.belongsTo(app.model.Student, {foreignKey: 'studentId', targetKey: 'id'});
}
return Info;
}
这里注意下，在sex字段中，有一个get(){}方法，因为在数据表里面，sex字段存了1或0 ，1为男0为女，为了直接返回"男"或"女"，这里使用get方法在找到数据后先做了处理，那返回给调用的函数的数据就是我们设置的值
- classes.js
module.exports = app => {
const { STRING, INTEGER, BOOLEAN } = app.Sequelize;
const Classes = app.model.define('classes', {
id: {
type: INTEGER,
autoIncrement: true,
primaryKey: true
},
name: {
type: STRING(50),
allowNull: false,
},
age: {
type: INTEGER,
allowNull: false
},
sex: {
type: BOOLEAN,
allowNull: false,
get() {
if ( this.getDataValue('sex') ){
return '男';
}else {
return '女';
}
}
},
studentId: {
type: INTEGER,
allowNull: false
}
});
Classes.associate = function (){
// classes与student是一对多关系，所以这里使用hasMany()
app.model.Classes.hasMany(app.model.Student, {foreignKey: 'classId', targetKey: 'id'});
}
return Classes;
}
- lession.js
module.exports = app => {
const { INTEGER, STRING } = app.Sequelize;
const Lession = app.model.define('lession', {
id: {
type: INTEGER,
primaryKey: true,
autoIncrement: true
},
name: {
type: STRING,
allowNull: false
}
});
Lession.associate = function(){
// 与student表是多对多关系
app.model.Lession.belongsToMany(app.model.Student, {
through: app.model.LessionStudent,
foreignKey: 'lessionId',
otherKey: 'studentId'
});
}
return Lession;
}
- lession-student.js
module.exports = app => {
const { INTEGER } = app.Sequelize;
const LessionStudent = app.model.define('lession_student', {
lessionId: {
type: INTEGER,
primaryKey: true
},
studentId: {
type: INTEGER,
primaryKey: true
}
});
LessionStudent.associate = function(){
}
return LessionStudent;
}
- 总结一下Model定义的内容
- 针对MYSQL常用的字段类型
字段类型从 app.Sequelize 获取，对应名字如下
Sequelize.STRING // VARCHAR(255)
Sequelize.STRING(1234) // VARCHAR(1234)
Sequelize.STRING.BINARY // VARCHAR BINARY
Sequelize.TEXT // TEXT
Sequelize.TEXT('tiny') // TINYTEXT
Sequelize.INTEGER // INTEGER
Sequelize.BIGINT // BIGINT
Sequelize.BIGINT(11) // BIGINT(11)
Sequelize.FLOAT // FLOAT
Sequelize.FLOAT(11) // FLOAT(11)
Sequelize.FLOAT(11, 12) // FLOAT(11,12)
Sequelize.DOUBLE // DOUBLE
Sequelize.DOUBLE(11) // DOUBLE(11)
Sequelize.DOUBLE(11, 12) // DOUBLE(11,12)
Sequelize.DECIMAL // DECIMAL
Sequelize.DECIMAL(10, 2) // DECIMAL(10,2)
Sequelize.DATE // DATETIME 针对 mysql / sqlite, TIMESTAMP WITH TIME ZONE 针对 postgres
Sequelize.DATE(6) // DATETIME(6) 针对 mysql 5.6.4+. 小数秒支持多达6位精度
Sequelize.DATEONLY // DATE 不带时间.
Sequelize.BOOLEAN // TINYINT(1)
其他的数据库所允许的类型参考：[数据类型](https://link.juejin.im?target=%255Bhttps%3A%2F%2Fdemopark.github.io%2Fsequelize-docs-Zh-CN%2Fmodels-definition.html%23%25E6%2595%25B0%25E6%258D%25AE%25E7%25B1%25BB%25E5%259E%258B%255D(https%3A%2F%2Fdemopark.github.io%2Fsequelize-docs-Zh-CN%2Fmodels-definition.html%23%25E6%2595%25B0%25E6%258D%25AE%25E7%25B1%25BB%25E5%259E%258B))
-
字段属性值
属性名 类型 默认值 说明 说明 type Any 无 是 数据类型 primaryKey Boolean false 否 主键 autoIncrement Boolean false 否 自增 allowNull Boolean false 否 是否允许为空 defaultValue Any 无 否 默认值 field String 字段名 否 自定义字段名 unique Any 无 否 约束 表与表的关联性
在sequelize中，表与表之间用代码来说存在三种关联关系：一对一，一对多，多对多
- 一对一
在该项目中，student表和info表是存在一对一关系的，一个学生有一条专属信息。
在student.js中，使用了hasOne()方法，第一个参数为关联的模型对象Info，第二个参数为一个对象，其包含一个属性为foreginKey为对应的信息表中studentId字段
在info.js中，使用了belongsTo()方法，第一个参数为关联的模型对象Student， 第二个参数也是一个对象，其有两个属性，foreginKey为info表中的"studentId"字段，第二个参数targetKey为student表中的"id"字段
总结： hasOne()和belongsTo()第一个参数为本表关联的另外一个表的Model实例，第二个参数中，都有foreginKey属性，对hasOne来说，这个属性值是对方表与自己Id对应的字段，对belongsTo来说，这个属性值是本表上的与对方表id对应的字段名。belongsTo比hasOne多了个targetKey属性，其为对方表的对应主键名
- 一对多
classes与student是一对多的关系，一个班级有多个学生，多个学生组成一个班级。
在student.js中，使用了belongsTo()，在classes.js中，使用了hasMany()，发现hasMany()与belongsTo()所需要的参数是类似的，但是这里注意，hasMany()里面的foreginKey值是对方表的classesId。结合第上面"一对一"的分析，我们可以总结出：
has开头的方法中，foreginKey属性值从对方的表上找，如果有targetKey的值则是自己的主键；
belongs开头的方法中，foreginKey属性值在自身表上找，targetKey属性值则是对方表上
- 多对多
分析多对多关系，一个学生有多门课，一个课有多个学生，那我们可以用一个中间表lession-student.js做这个联系。
在student.js中，我们使用了belongsToMany()方法，lession.js文件中也是如此，通过该方法的参数内容，可以发现其多了一个through属性，其值是中间表的Model实例。根据上面的规律，belongs开头的方法里面foreginKey找自己，otherKey找其他，所以很容易理解。
总结： 在Model的实例里面，重写Model的associate方法，将关联的关系放到里面。
一对一的方法有：
hasOne(Model, {foreignKey:对方,})和belongsTo(Model,{foreignKey:自己,targetKey:对方})一对多的方法有：
hasMany(Model,{foreignKey:对方, targetKey:自己})和belongsTo(Model,{foreignKey:自己,targetKey:对方})多对多的方法有：
belongsToMany(Model,{through:Model, targetKey:自己, otherKey:对方})
3.联表查询
- 一对一
在controller里面如下写
// 获取学生信息 通过一对多的联系
async info(){
const { ctx, app } = this;
let result = await app.model.Student.findAll({
include: {
model: app.model.Info
}
});
ctx.body = result;
}
获取到的值如下：
[
// 第一个学生
{
"id": 1,
"number": "160101",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:16:09",
"updatedAt": "2019-05-12 13:16:12",
"deletedAt": null,
"info": { // 联表查到的信息
"sex": "男",
"id": 1,
"name": "许仙",
"age": 23,
"studentId": 1,
"createdAt": "2019-05-12 13:25:58",
"updatedAt": "2019-05-12 13:26:01",
"deletedAt": null
}
},
// 第二个学生
{
"id": 2,
"number": "160201",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 2,
"createdAt": "2019-05-12 13:16:32",
"updatedAt": "2019-05-12 13:16:35",
"deletedAt": null,
"info": {
"sex": "女",
"id": 2,
"name": "白素贞",
"age": 20,
"studentId": 2,
"createdAt": "2019-05-12 13:26:41",
"updatedAt": "2019-05-12 13:26:46",
"deletedAt": null
}
},
{
"id": 3,
"number": "160102",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:17:17",
"updatedAt": "2019-05-12 13:17:21",
"deletedAt": null,
"info": {
"sex": "男",
"id": 3,
"name": "法海",
"age": 22,
"studentId": 3,
"createdAt": "2019-05-12 13:27:20",
"updatedAt": "2019-05-12 13:27:22",
"deletedAt": null
}
},
{
"id": 4,
"number": "160103",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:17:51",
"updatedAt": "2019-05-12 13:17:54",
"deletedAt": null,
"info": {
"sex": "女",
"id": 4,
"name": "小青",
"age": 18,
"studentId": 4,
"createdAt": "2019-05-12 13:27:48",
"updatedAt": "2019-05-12 13:27:51",
"deletedAt": null
}
},
{
"id": 5,
"number": "160104",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:18:13",
"updatedAt": "2019-05-12 13:18:16",
"deletedAt": null,
"info": {
"sex": "女",
"id": 5,
"name": "金如意",
"age": 20,
"studentId": 5,
"createdAt": "2019-05-12 13:28:34",
"updatedAt": "2019-05-12 13:28:37",
"deletedAt": null
}
},
{
"id": 6,
"number": "160202",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 2,
"createdAt": "2019-05-12 13:18:36",
"updatedAt": "2019-05-12 13:18:39",
"deletedAt": null,
"info": {
"sex": "男",
"id": 6,
"name": "景松",
"age": 23,
"studentId": 6,
"createdAt": "2019-05-12 13:30:07",
"updatedAt": "2019-05-12 13:30:10",
"deletedAt": null
}
}
]
- 一对多
// 获取班级名为 软件工程1601 的班级学生
async student(){
const { ctx, app } = this;
let result = await app.model.Classes.findAll({
where: {
name: '软件工程1601'
},
include: {
model: app.model.Student
}
})
ctx.body = result;
}
获取数据如下：
[
{
"id": 1,
"name": "软件工程1601",
"createdAt": "2019-05-12 13:11:43",
"updatedAt": "2019-05-12 13:11:47",
"deletedAt": null,
"students": [
{
"id": 1,
"number": "160101",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:16:09",
"updatedAt": "2019-05-12 13:16:12",
"deletedAt": null
},
{
"id": 3,
"number": "160102",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:17:17",
"updatedAt": "2019-05-12 13:17:21",
"deletedAt": null
},
{
"id": 4,
"number": "160103",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:17:51",
"updatedAt": "2019-05-12 13:17:54",
"deletedAt": null
},
{
"id": 5,
"number": "160104",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:18:13",
"updatedAt": "2019-05-12 13:18:16",
"deletedAt": null
}
]
}
]
- 多对多
从学生获取课程信息
// 获取学生的选课内容
async lession(){
const { ctx, app } = this;
let result = await app.model.Student.findAll({
where:{
id: 1,
},
include: [
{model: app.model.Info},
{model: app.model.Lession}
]
});
ctx.body = result;
}
这里的话，注意include的值为一个数组了，这样可以多个联表获取数据
数据如下：
[
{
"id": 1,
"number": "160101",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 1,
"createdAt": "2019-05-12 13:16:09",
"updatedAt": "2019-05-12 13:16:12",
"deletedAt": null,
"info": {
"sex": "男",
"id": 1,
"name": "许仙",
"age": 23,
"studentId": 1,
"createdAt": "2019-05-12 13:25:58",
"updatedAt": "2019-05-12 13:26:01",
"deletedAt": null
},
"lessions": [
{
"id": 1,
"name": "计算机网络",
"createdAt": "2019-05-12 13:12:32",
"updatedAt": "2019-05-12 13:12:35",
"deletedAt": null,
"lession_student": {
"lessionId": 1,
"studentId": 1,
"createdAt": "2019-05-12 13:20:35",
"updatedAt": "2019-05-12 13:20:40",
"deletedAt": null
}
},
{
"id": 2,
"name": "Java程序设计",
"createdAt": "2019-05-12 13:12:50",
"updatedAt": "2019-05-12 13:12:52",
"deletedAt": null,
"lession_student": {
"lessionId": 2,
"studentId": 1,
"createdAt": "2019-05-12 13:23:10",
"updatedAt": "2019-05-12 13:23:13",
"deletedAt": null
}
},
{
"id": 3,
"name": "软件项目管理",
"createdAt": "2019-05-12 13:13:07",
"updatedAt": "2019-05-12 13:13:10",
"deletedAt": null,
"lession_student": {
"lessionId": 3,
"studentId": 1,
"createdAt": "2019-05-12 13:24:21",
"updatedAt": "2019-05-12 13:24:24",
"deletedAt": null
}
}
]
}
]
从课程获取选课学生：
// 获取某个课的参课学生
async lessionStudent(){
const { ctx, app } = this;
let result = await app.model.Lession.findAll({
where:{
name: '网络安全'
},
include: {
model: app.model.Student,
include: {
model: app.model.Info
}
}
});
ctx.body = result;
}
这里注意，在include的下面又有一个include，第二个include是相对Student表的
数据如下：
[
{
"id": 4,
"name": "网络安全",
"createdAt": "2019-05-12 13:13:22",
"updatedAt": "2019-05-12 13:13:25",
"deletedAt": null,
"students": [
{
"id": 2,
"number": "160201",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 2,
"createdAt": "2019-05-12 13:16:32",
"updatedAt": "2019-05-12 13:16:35",
"deletedAt": null,
"lession_student": {
"lessionId": 4,
"studentId": 2,
"createdAt": "2019-05-12 13:24:59",
"updatedAt": "2019-05-12 13:25:03",
"deletedAt": null
},
"info": {
"sex": "女",
"id": 2,
"name": "白素贞",
"age": 20,
"studentId": 2,
"createdAt": "2019-05-12 13:26:41",
"updatedAt": "2019-05-12 13:26:46",
"deletedAt": null
}
},
{
"id": 6,
"number": "160202",
"password": "202cb962ac59075b964b07152d234b70",
"classId": 2,
"createdAt": "2019-05-12 13:18:36",
"updatedAt": "2019-05-12 13:18:39",
"deletedAt": null,
"lession_student": {
"lessionId": 4,
"studentId": 6,
"createdAt": "2019-05-12 13:25:12",
"updatedAt": "2019-05-12 13:25:15",
"deletedAt": null
},
"info": {
"sex": "男",
"id": 6,
"name": "景松",
"age": 23,
"studentId": 6,
"createdAt": "2019-05-12 13:30:07",
"updatedAt": "2019-05-12 13:30:10",
"deletedAt": null
}
}
]
}
]
4. 总结
用时4小时，调试加数据库设置，代码编写，查文档。允许我偷个懒，不想总结了，仔细阅读内容，基本上可以了解Sequelize在联表查询上的基本用法了
