README

sql-to-mongo

Cli tool to export data from sql database to mongo using simple SQL queries. (We only support PostgreSQL for now)

Inspired by this article from Containerum.

Installation

Use npm to install the cli.

npm install -g sql-to-mongo

You can verify that the installation was succesful with:

s2m --version

Usage

Suppose you have a sqlDb with a customers table :

CustomerID	CustomerName	City	PostalCode	Country
1	Alfreds Futterkiste	Berlin	12209	Germany
2	Ana Trujillo Emparedados y helados	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	México D.F.	05023	Mexico

Write an sql query to define the data you want to export and save it to a file with the name that the mongo collection should have:

.../exports/customers.sql

SELECT  "CustomerName" as customerName , "City" as city, "PostalCode" as cp FROM customers;

Sql queries can be as complex as you need. You can make joins or even create nested structures with functions such as row_to_json or array_to_json. Read the original article from Containerum for examples.

Write your connection data in a config file (default location and name is ./s2m.config.js):

s2m.config.js

module.exports = {
    exportsDirPath: './exports',
    sqlDbConfig: {
        host: 'localhost',
        port: 5432,
        database: 'sqlDbName',
        username: 'admin',
        password: 'admin'
    },
    mongoDbConfig: {
        connectionString: 'mongodb://admin:admin@localhost:27017',
        dbName: 'mongoDbName'
    }
}

Test run your exports with --dry-run. This will only output the data to console and won't write to Mongo.

s2m --dry-run

{
    customerName: "Alfreds Futterkiste",
    city: "Berlin",
    cp: 12209
},
{
    customerName: "Ana trujillo Emparedados y helados",
    city: "México D.F",
    cp: 05021
}
...

To have the export data written to Mongo simply run.

s2m

BeforeAll and AfterAll hooks

In your exports directory you can add beforeAll.js and afterAll.js files to execute arbitrary Mongo's node js driver instructions before and after the exports are executed :

For instance you can clean the collections before insertion :

.../exports/beforeAll.js

modules.exports = async function(db) {
    await db.collection('customers').deleteMany({})
}

Or you can make arbitrary transforms after the data was imported into Mongo

.../exports/afterAll.js

modules.exports = async function(db) {
    await db.collection('customers').updateMany({}, {$set: {createdAt: new Date()}});
}

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT

Usage no npm install needed!