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
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:
const BaseDatabaseOps = require("path/to/this/class")
class AddressDB extends BaseDatabaseOps {
constructor() {
super('address')
}
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> >