@xavisoft/mongoose-cascade

@xavisoft/mongoose-cascade

This npm package enables easy implementation of ON DELETE CASCADE, SET NULL, and RESTRICT behaviors in Mongoose schemas for MongoDB databases.

Unlike SQL-based databases, MongoDB does not provide these features by default. This package fills this gap by simplifying the configuration of cascading operations in your MongoDB databases, ensuring referential integrity in your database schemas.

Installation

npm install @xavisoft/mongoose-cascade

Example

const { default: mongoose, Schema } = require("mongoose");
const { Cascade, constants } = require('@xavisoft/mongoose-cascade');
const { ON_DELETE } = constants;

// create models
const User = mongoose.model('User', new Schema({
   name: String,
   surname: String,
}));

const Comment = mongoose.model('Comment', new Schema({
   text: String,
   user: {
      type: mongoose.SchemaTypes.ObjectId,
      ref: 'User',
      onDelete: ON_DELETE.SET_NULL,
   },
   createdAt: Date,
}));

// create docs
const cap = await User.create({
   name: 'Steve',
   surname: 'Rogers',
});

const comment = await Comment.create({
   text: 'I can do this all day!',
   user: cap._id,
   createdAt: new Date(),
});

// delete
const cascade = new Cascade();
cascade.init();

await cascade.delete(User, { _id: cap._id });

// check
const updatedComment = await Comment.findById(comment._id);
console.log(updatedComment.user); // output: null

Documentation

onDelete

To configure on delete behavior for your references, provide onDelete value with your schema references as shown in the above example, with one of the values below:

• ON_DELETE.SET_NULL: Set the references to the document(s) being deleted to null
• ON_DELETE.CASCADE: Delete all the document referencing the document(s) being deleted
• ON_DELETE.RESTRICT: Do not delete if there are still documents referencing the document(s). Instead raise a DeleteRestrictedError
• ON_DELETE.PULL: Apply the $pull operator on the array to remove items referencing document(s) being deleted

Cascade

• Cascade
  • new Cascade(conn)
  • .delete(Model, filter, opts)
  • .init()

new Cascade(conn)

Param	Type	Description
conn	mongoose.Connection	The mongoose connection to use. Defaults to mongoose.connection

cascade.delete(Model, filter, opts)

Method to delete, cascading as per schema definitions

Param	Type	Description
Model	mongoose.Model	The model to delete from
filter	object	the where clause
opts	object
opts.session	mongoose.ClientSession	Provide this if the deletion needs to be part of an already started transaction

cascade.init()

Initializes the instance. Throws an error if something is wrong with your schemas