如何使用node.js控制sequelize中的内连接查询？

Posted 2023-03-07

【中文标题】如何使用node.js控制sequelize中的内连接查询？

【英文标题】：How to control the inner join query in sequelize using node.js?

【发布时间】：2019-04-22 05:13:52

【问题描述】：

天模型：

workoutId: 
    type: Sequelize.INTEGER,
,
traineeId: 
  type: Sequelize.INTEGER,
  primaryKey: true
,
dayNumber: 
  type: Sequelize.INTEGER,
  primaryKey: true
,
status: 
  type: Sequelize.INTEGER
,

WorkoutsExercises 模型：

workout_id: 
  type: Sequelize.INTEGER,
  primaryKey: true
,
exercise_name: 
  type: Sequelize.INTEGER,
  primaryKey: true
,
coach_id: 
  type: Sequelize.INTEGER,
  primaryKey: true

我只是想在两个表之间进行内部连接以返回每天的所有练习，我使用以下

const Days = require('../models/days');
const WorkoutsExercises = require('../models/workoutsExercises');

Days.findAll(
  include: [
    model: WorkoutsExercises,
      required: true
   ]        
)

此函数返回以下查询：

SELECT
  `day`.`workoutId`,
  `day`.`dayNumber`,
  `day`.`status`,
  `day`.`traineeId`,
  
  `workoutsExercises`.`workout_id` AS `workoutsExercises.workout_id`, 
  `workoutsExercises`.`exercise_name` AS `workoutsExercises.exercise_name`, 
  `workoutsExercises`.`coach_id` AS `workoutsExercises.coach_id`

FROM `days` AS `day`

INNER JOIN `workoutsExercises` AS `workoutsExercises` 

ON `day`.`dayNumber` = `workoutsExercises`.`workout_id`; 

如何将开启条件从 (day.dayNumber) 更改为 (day.workoutId)

【参考方案1】：

如果您在两个模型之间有多个关系，您可以创建多个关联：

User.hasMany(Task);
Task.belongsTo(User);

User.hasMany(Task, as: "secondAssociation", foreignKey, sourceKey);
Task.belongsTo(User, as: "secondAssociation", foreignKey, targetKey);

您可以使用不同的 ON 子句运行此查询，该子句由您提供的用于创建关联的 foreignKey（和 sourceKey/targetKey）值确定：

User.findAll(
  include: [
    model: Task
  ]

User.findAll(
  include: [
    model: Task,
    as: "secondAssociation"
  ]
)

如果要更改给定查询的 ON 子句，可以使用 Model.findAll 方法的 include[].on 选项。

User.findAll(
  include: [
    model: Task,
    on:  //Use Sequelize.Op.col for reference on other column
  ]

【参考方案2】：

关系应该如下

WorkoutExercises.hasMany(Day, foreignKey: 'workout_id')
Day.belongsTo(WorkoutExercises, foreignKey: 'workout_id', targetKey: 'workout_id')

目标键是改变 ON 子句的原因，我们将使用相同的查询：

Days.findAll(
  include: [
    model: WorkoutsExercises,
    required: true
  ]        
)

给出：

SELECT

  `day`.`dayNumber`,
  `day`.`dayDate`,
  `day`.`status`,
  `day`.`traineeId`, 
  `day`.`workoutId`, 

  `workoutsExercises`.`exercise_name` AS `workoutsExercises.exercise_name`,
  `workoutsExercises`.`workout_id` AS `workoutsExercises.workout_id`,
  `workoutsExercises`.`coach_id` AS `workoutsExercises.coach_id`
 
 FROM `days` AS `day`
 
 INNER JOIN `workoutsExercises` AS `workoutsExercises`
 
 ON `day`.`workout_id` = `workoutsExercises`.`workout_id`;