I have a NodeJS project running with mongodb database (using mongoose).
For a technological constraint reason I need to migrate the app from using mongodb to mysql - is there a way to migrate to mysql without having to rewrite the whole mongoose model files?
PS. although I'm using mongodb all the query is mainly still not on the nested document (I'm querying only by ID or by some first-level attribute) so actually putting nested document into a field in mysql table should still be fine
I would suggest letting your application run with Mongo for now. Meanwhile write a wrapper for MySQL that would translate your Mongo queries to mysql. Switch to that wrapper once done. Then write another wrapper for Mongo, just in case you need to switch back.
Try and keep all your Database specific function calls in the wrapper. So, that you won't need to do this again and again. Just write a new wrapper for whatever Database you will use and just switch.
And you'll probably need to run some sort of job to migrate your data from Mongo to MySQL.
Related
I have been working on a project lately and using node as my back-end but instead of Mongodb I am using MySQL as my DBMS as I will need it in my project but I am having trouble organizing MySQL queries and can't find a good solution that helps me structure my code and files right. And another issue is that I don't know when to close my connection or if leaving it is a good practice or not.
NOTE: I already use express generator for generating my file architecture my only problem is where to place the MySQL related code and what are the best practices for a clean code.
You can create a model folder and add all your 'tables'.js there.
You can also create a DB.js file, so you can use Mysql from Nodejs and also manipulate it from the prompt:
Model Exemple
I.e of DB connection:
DB Connection
You can create tables on the way below. ID's, creating date and updated date are created automatically by Nodejs, so you don't need to worry about.
how to create a table
You also will need to download mySQL (npm install MySQL --save) and to interact with MySQL (selects, deletes,...)
Another way is create a repository.js and add SQL queries there, but is not really useful since you are using nodejs and it provides you these queries.
I want to create an api rest with laravel, and I have already designed my database. However, laravel doesn't allow me to create composite keys. Therefore, my question is, what could happen if instead of using migrations in laravel, I just create my database with sql and then make the corresponding connection?
You are free to do anything. You can even overwrite laravel as you wish. You have full control over laravel app. You can do whatever you like. Migration is there to assist you on many ways to create, update your database. This is no difference to what you would do without using it. It will not effect your application. You can import sql, Build your own schema. do whatever you want.
I am planning to use Postgres as my database and sequelize as my ORM framework one of my NodeJS project. I need your suggestion on how to accomplish database table changes in production enviroment.
For example , we deployed our version-1 application with some database schema.
Later , there is a change in my schema in Version-2. Say one of the table is altered and few columns are dropped and few columns are added.
Also one of the table itself is not required in Version-2.
In my production , I have some database with data. When I install Version-2 of my NodeJS application , I need to keep the old data as it is and apply the new database schema of Version-2.
How to achieve this , Let me point out some reference to this.
Thanks
Sequelize (or rather, sequelize-cli) has built in support for migrations.
You can write migrations using the Sequelize js api (e.g. queryInterface.dropColumn('users', 'address')) or write raw SQL and pass it to sequelize.query()
I'm playing around with expressjs for a while and now the time has come to connect to a mysql database. Now i'm searching for a way to write and retrieve data from it. Normally i'm creating the database tables with MySQL Workbench. I'm using MySQL because of the ability of using ForeignKeys. Couldn't figure out yet how to do it in other database types...
Currently i'm more used to medoo for PHP. It only connected to a database and gave me the ability to access it in an object oriented way.
Is there a similar module for nodejs out there?
Try knex for a sql-builder library, it's pretty solid and looks sort of similar to medoo (but it uses Promises and is asynchronous).
I'm trying to make some reports using meteor and raphael js. I have to report data from an existing MySQL database. I do not wish to write to that database. I need only the "R" from CRUD.
I have thought of various manual ways of: exporting .csv files from the MySQL db via the application itself (Limesurvey) and using mongoimport to populate a MongoDB collection, and then do my CollectionName.find() etc in Meteor.
or perhaps some way of exposing REST full endpoints only to consume data, and use the http package for Meteor.
Is there a good clean solution for using existing SQL data in a Meteor JS application?
How can one use pre-existing SQL data?
(I've no problem with duplication in MongoDB, mind you. however it has to be...)
Thank You
You can do it without any duplication completely from inside Meteor, but you will have to jump through a couple of hoops.
Firstly, use the mysql npm package to query the SQL database. Though Meteor provides Npm to require node packages, I find that using meteor-npm is an easier. Then to do the "R"eading form MySQL, create a Meteor.method on your server which queries the MySQL directly.
Then the second problem is that the mysql package is completely asynchronous. Hence, the execution of the SQL query returns value in a call back and by that point, your Meteor.method call would return leaving the client with an undefined. To fix that issue, we can use Future.
There are a couple of ways of smoothing over this step:
Using `meteor-sync-methods
Spinning out your own version from advice from the issue to allow this natively
Use this easy to implement one-time pattern: "fence has already activated -- too late to add writes"
Hope that helps.