Change column name Sequilize - node.js

Question

I want to change default column name in my final output which comes from Mysql database when i am accessing database using NodeJS and Sequelize connection.
I am connecting using following code:-
import Sequelize from "sequelize";
let dbConnection = new Sequelize('DB', 'abc', 'password', {
host: '127.0.0.1',
port: 4242,
dialect: 'mysql',
dialectOptions: {
requestTimeout: 0,
},
});
const Listing = dbConnection.define('TableName', {
tour_title: {
type: Sequelize.STRING,
}
}, { freezeTableName: true, timestamps: false });
For example, I want to change tour_title by tour_name in the above column only in the final sequelize output. I do not want any change in database column names.

Answer 1

To change column name only in final output
TableName.findAll({
attributes: ['id', ['tour_title', 'tour_name']] /
})
.then((data) => {
console.log(data);
});
To change column name in database
This may help you, follow this steps
Step 1: npm install -g sequelize-cli
To install sequelize command line tool
Step 2: sequelize migration:create --name rename-column-tour_title-to-tour_name-in-tabelname
Step 3: Open newly created migration file and add below code
'use strict';
module.exports = {
up: (queryInterface, Sequelize) => {
return queryInterface.renameColumn('tableName', 'tour_title', 'tour_name');
},
down: (queryInterface, Sequelize) => {
return queryInterface.renameColumn('tableName', 'tour_name', 'tour_title');
}
};
Step 4: in command line run this below command
sequelize db:migrate
Now your column name changed successfully.

Answer 2

If you want an alias for a column name in the ouput , you can do something like this:
TableName.findAll({
attributes: ['id', ['tour_title', 'tour_name']] //id, tour_title AS tour_name
})
.then(function(data) {
res.json(data);
});
Whenever you fetch any records you can write the column name in a cascaded list and make an alias.
Check for the documentation here : http://docs.sequelizejs.com/manual/tutorial/querying.html

Answer 3

The above answers only works for the query results. If you want to keep your underscore name convention on the database and use for example camelCase for your javascript environment you need to do this:
const ChildTable = dbConnection.define('ChildTable', { //this table name is how you call it on sequelize
tourTitle: { //this is the name that you will use on javascript
field: 'tour_title', // this will be the name that you fetch on your db
type: Sequelize.STRING,
},
parentTableId: { // You need to define the field on the model, otherwise on sequelize you'll have to use the db name of the field
field: 'parent_table_id', //this is defined above on the association part
type: Sequelize.INTEGER,
}
}, { freezeTableName: true, timestamps: false, tableName: 'TableName', //this is the real name of the table on the db
underscored: true, });
ChildTable.associate = (models) => {
ChildTable.belongsTo(models.ParentTable, { as: 'ParentTable', foreignKey: 'parent_table_id', onDelete: 'cascade' });
};
This way you have an "alias" for your fields on all the Sequelize / javascript environment and you keep your names on the db. See also that you have to do the same with the foreign keys on associations, otherwise you'll have to use the original name.

Answer 4

I'd add something to #Deepak's answer. When I tried it the Step 4: (I am a newbie), it prompted that
"Cannot find config.json Have you run sequelize init? "
Then I executed that init command then it made a config.json file inside the config folder. So the file contained below objects.
{
"development": {
"username": "root",
"password": null,
"database": "database_development",
"host": "127.0.0.1",
"dialect": "mysql"
},
"test": {
"username": "root",
"password": null,
"database": "database_test",
"host": "127.0.0.1",
"dialect": "mysql"
},
"production": {
"username": "root",
"password": null,
"database": "database_production",
"host": "127.0.0.1",
"dialect": "mysql"
}
}
Then I executed the sequelize db:migrate. It prompted another error as
Sequelize CLI [Node: 18.7.0, CLI: 6.4.1, ORM: 6.21.4]
Loaded configuration file "config\config.json".
Using environment "development".
ERROR: Access denied for user 'root'#'localhost' (using password: NO)
Then what I did was I changed the config.json file to something like this -->
{
"development": {
"username": "root",
"password": "<this should include your root password>",
"database": "<this should include your db>",
"host": "127.0.0.1",
"dialect": "mysql"
},
"test": {
"username": "root",
"password": null,
"database": "database_test",
"host": "127.0.0.1",
"dialect": "mysql"
},
"production": {
"username": "root",
"password": null,
"database": "database_production",
"host": "127.0.0.1",
"dialect": "mysql"
}
}
And then migration was done successfully!