Creating Primary and Foreign Key relations in Sequelize - mysql

Question

I have 2 models Project model and Task model defined in sequelize as shown below
import { INTEGER, STRING, DATE } from 'sequelize';
import sequelize from '../sequelize';
import Task from './task.model'
const ProjectModel = sequelize.define('project', {
project_id: {
type: INTEGER,
primaryKey: true,
autoIncrement: true
},
phabricator_project_id: {
type: STRING,
allowNull: false
},
name: {
type: STRING
},
description: {
type: STRING
},
start_date: {
type: STRING,
},
end_date: {
type: STRING
}
},
{
timestamps: false
}
);
export default ProjectModel;
and the task model
import { INTEGER, STRING, DATE } from 'sequelize';
import sequelize from '../sequelize';
const TaskModel = sequelize.define('task', {
task_id: {
type: INTEGER,
primaryKey: true,
autoIncrement: true
},
title: {
type: STRING
},
status: {
type: STRING
},
priority: {
type: STRING
},
description: {
type: STRING
},
tool_project_id: {
type: STRING
},
date_modified: {
type: STRING
}
},
{
timestamps: false
}
);
export default TaskModel;
What I want to achieve is to create a relation between tool_project_id in TaskModel and phabricator_project_id in ProjectModel (they are same values only diff column names are given) and write a query for a GET request which outputs the data in form shown below
{ {project1Details,TaskDetails-->{task1, task2, task3},
{project2Details,TaskDetails-->{task4, task5, task6},
{project3Details,TaskDetails-->{task7, task8, task9},
{project4Details,TaskDetails-->{task10, task11, task12} }
All the database design has been done accordingly and another file is called to create all these databases. This is written in typescript and I tried this as a GET method
listByProjects(req, res) {
TaskModel.belongsTo(ProjectModel, { as: 'task' , foreignKey: 'tool_project_id'});
ProjectModel.findAll({
include:[{model:TaskModel}],
where:{status:'open'}
}).then(function(projects) {
res.json(projects);
});
}
Here in this method I define the relation and try to list all 'open' tasks and send them back as response but I am getting the error
Unhandled rejection Error: task is not associated to project!
ANY HELP TO THIS PROBLEM WOULD BE WONDERFULL

Answer 1

The answer to this question is that when creating the table we should create the relation and then create the table such as
Create the relation also the name of the key should be same so as to create relation.
TaskModel.belongsTo(ProjectModel, {foreignKey: 'project_id' });
ProjectModel.hasMany(TaskModel, { foreignKey: 'project_id' });
Then create the table project and then tasks
ProjectModel.sync({ force: false }).then(function () {
console.log('Project table created');
TaskModel.sync({ force: false }).then(function () {
console.log('Task table created');
});
});
then in the API method, you are invoking just include the model which you want to provide to get the required data.
ProjectModel.findAll({
include: [{
model: TimeSheetModel,
where: {
status: "ACTIVE"
},
}],
}).then(function (projects) {
const responseData = {
'status': 1,
'message': 'List successfull.',
'projects': projects,
};
res.json(responseData);
}).catch(error => {
const responseData = {
'status': 1,
'message': error.message,
'projects': [],
};
res.json(responseData);
})
This uses nodemon and sequilize to manage node and relations of the table respectively