baseDatabaseOps

Creates an object with base database operations which can then be extended and overridden as required for each collection.

the goal of this class is create a base object that has the basic required methods for average database collection which can be quickly modified and exported for each collection.

basic usage

//address database ops index.js file

const BaseDatabaseOps = require("path/to/this/class")

class AddressDB extends BaseDatabaseOps {
    constructor() {
        super('address')
    }
  
}
exports = module.exports = AddressDB

and as the required methods are already implemented in this base class it will take care of them such as writeOne, writeMany, readOne, readMany, list, updateOne, updateMany, removeOne, removeMany.

overriding

And if we ever need to change a method we can just override it.

For example let's say we want our readOne so that we can resolve/populate the customer field with customer info from the customer collection if required. Here is how we would approach the implementation:

//address database ops index.js file

const BaseDatabaseOps = require("path/to/this/class")

class AddressDB extends BaseDatabaseOps {
    constructor() {
        super('address')
    }

    //example for overriding method
    async function readOne(id, resolve = {}) {
        
        const aggregatePipeline = [];
        aggregatePipeline.push({
            $match: {
                _id: { $in: id.map(i => new client.ObjectID(i)) }
            }
        })
        if(resolve.customer){
            aggregatePipeline.push({
                $lookup: {
                    from: "customer",
                    localField: "customer",
                    foreignField: "_id",
                    as: "customer"
                }
            },
            {
                $unwind: {
                    path: "$customer",
                    preserveNullAndEmptyArrays: true
                }
            }
            )
        }
        
        const db = await this.getDB();
        const result = await db.collection("address").aggregate(aggregatePipeline).toArray();
        return result;

    }


}
exports = module.exports = AddressDB

parameters

• collectionName string - name of the database collection

Note 1

Even though the base readOne, readMany method supports resolve parameter, it won't respond to them. If resolving in needed for any collection than it should be implemented by overriding the base methods. A warning will be printed on the console every time any property is passed in the resolve param.

Note 2

Even though the base list method supports resolve and filter parameter, it won't respond to them. If filtering and resolving in needed for any collection than it should be implemented by overriding the base methods. A warning will be printed on the console every time any property is passed in the filter or resolve param.

Methods

• getDB(): Promise< object: databaseInstance >
• getCollection( ): Promise< object: dbCollectionInstance >
• getClient(): Promise< object: databaseClientInstance >
• writeOne( entity:object ) : Promise< object >
• writeMany( entityList: Array<object> ) : Promise< Array<object> >
• updateOne( id: string, entity: object ) : Promise< object >
• updateMany( entityList: Array<object> ) : Promise< Array<object> >
• readOne( id: string, entity: object ) : Promise< object >
• readMany( id: string, resolve: object ) : Promise< Array<object> >
• list( filter?: object, resolve?: object, paginateOptions?: object) : Promise< Array<object> >
• removeMany(id: string): Promise< object >
• removeOne(idList: Array<string>): Promise< Array<object> >