vEden MongoDB

Purpose

This package is a wrapper for the mongodb nodejs client

Usage

const MongoDatabase = require('veden-mongodb').MongoDatabase;
const db = new MongoDatabase({
    DB_HOSTS : "localhost",
    DB_REPLICA_SET : "test",
    DB_USER : "admin",
    DB_PASS : "secret123"
});
// This will connect to the url: `mongodb://admin:secret123@localhost/?replicaSet=test`


let db_params = {
    database: "users",
    collection: "user",
    limit: 10,
    fields: ["username","email"],
    exclude_fields: ["_id"],
    sort:{
        field: "_id",
        order: "asc"
    }
};
db.find(db_params,{email:/.*@gmail.com/g}).then(result => {
    /* Use data */
});

Default Parameters

All methods take DB Parameters as the first argument, which can be;

database: Database to connect to
collection: Collection to use
limit: number of docs to return
fields: fields to include in result
exclude_fields: fields to exclude from result
sort.field: Sort by given field ascending by default
sort.order: "asc" or "desc"

The Second argument is the query, uses mongodb query syntax. Default is empty query (return all documents).

Write operations (insert, update, etc) take the document in the third argument

All methods return promises which resolve to their return type

Available Methods

getCursor()

Runs a find() with the given query and returns the resulting mongodb cursor object

count()

Returns an integer with the matching document count

find()

Returns an array with all matching documents

findOne()

Returns only the matching document

insertOne()

Returns

• _id: ObjectId of inserted document
• result: Raw Response from database (varies by mongo version)

insertMany()

Returns

• _ids: Array of ObjectIds of inserted documents
• result: Raw Response from database (varies by mongo version)

replaceOne()

Returns

• matched: Number of matched documents
• modified: Number of modified documents
• upserted: Number of upserted documents
• upserted_id: Id of created document if upserted
• result: Raw Response from database (varies by mongo version)

upsertOne()

Returns

• matched: Number of matched documents
• modified: Number of modified documents
• upserted: Number of upserted documents
• upserted_id: Id of created document if upserted
• result: Raw Response from database (varies by mongo version)

updateOne()

Returns

• matched: Number of matched documents
• modified: Number of modified documents
• result: Raw Response from database (varies by mongo version)

updateMany()

Returns

• matched: Number of matched documents
• modified: Number of modified documents
• result: Raw Response from database (varies by mongo version)

deleteOne()

Returns

• deleted: count of deleted documents

deleteMany()

Returns

• deleted: count of deleted documents

aggregate()

Allows you to use mongodb's aggregation pipeline

db.aggregate(db_params,[ ... aggregations ]).then(result => { ... })

startTransaction(opts,callback) => Promise

Starts a new ClientSession, begins a transaction and provides the required db_params in a callback. The transaction is commited when the callback resolves, and aborted if it throws an error.

opts

• retries default: 3 - Number of Retries before throwing error
• delay default: 1000 - Delay in ms before retrying
• database default: none - Default DB to provide in params
• collection default: none - Default collection to provide in params
• retry_error_codes default: [251,112] - Error codes to retry on

callback

• Recieves params object which can be passed to other db methods
• Must return a Promise (async / await does this automatically)
• Result will be resolved by the runTransaction function when the transaction finishes
• params:
  • session - always present, ClientSession with running transaction, pass into db_params for operation to be within the session
  • database - present if provided in opts
  • collection - present if provided in opts

db.runTransaction({database: 'db1'},(params) => {
    return Promise.all([
        db.updateOne(
            {database: params.database, collection: 'collection1', session: params.session},
            {},
            {closed: true}
        ),
        db.updateMany(
            {database: params.database, collection: 'collection2', session: params.session, overwrite: true},
            {name:"update doc"},
            {$push:{_ids: "update"}}
        )
    ]);
}).then(([result1,result2]) => {
    // Transaction successful
}).catch(e => {
    // Transaction Failed
})