@eldoy/memdb

MemDB

A lightweight, in-memory JSON database for Node.js designed for speed and simplicity. Intended for single-process environments only.

memdb keeps all data strictly in memory. There is no persistence.

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* Mongo-style Queries: $gt, $lt, $gte, $lte, $ne, $in, $nin, $regex
* In-memory Only: All reads and writes operate on live memory
* Date Support: Automatic normalization and comparison of Date values
* Sorting: Multi-key ascending / descending sort
* Pagination: Built-in limit and skip
* Minimal API: Only get() and set()
* Synchronous Writes: set() is fully synchronous

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``sh
npm i memdb
`

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`js
var memdb = require('memdb')

// Single in-memory collection
var db = memdb()

db.set({ type: 'user', name: 'Alice' })
db.set({ type: 'user', name: 'Bob' })

var users = db.get({ type: 'user' })
`

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#### 1. Inserting Data

Passing a single object inserts a new document. A UUID id is generated automatically if missing.

`js
db.set({
name: 'Project Alpha',
status: 'pending',
priority: 1,
createdAt: new Date()
})
`

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#### 2. Querying with Operators

`js
// Numeric and inequality operators
var tasks = db.get({
priority: { $gte: 5 },
status: { $ne: 'archived' }
})

// Regex and array operators
var results = db.get({
name: { $regex: /^Project/i },
tags: { $in: ['urgent', 'active'] }
})
`

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#### 3. Updating Data

`js
// Update all pending tasks
db.set({ status: 'pending' }, { status: 'active' })

// Update by ID
db.set({ id: 'some-uuid' }, { progress: 100 })
`

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#### 4. Deleting Data

`js
// Delete a single record
db.set({ id: 'some-uuid' }, null)

// Delete all completed tasks
db.set({ status: 'completed' }, null)

// Clear entire database
db.set({}, null)
`

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#### 5. Pagination and Sorting

`js
var page = db.get(
{ type: 'log' },
{ sort: { createdAt: -1 }, limit: 10, skip: 10 }
)
`

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| Method | Description |
| ----------------------- | ------------------------------------------------------------- |
| get(query, [options]) | Returns matching documents. Supports { limit, skip, sort }. |
| set(query, [values])` | Insert, update, or delete documents. |

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* All data lives in memory
* No filesystem access
* No async behavior
* No background work
* Process exit discards all data

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* Single process only
* No persistence
* No transactions
* No indexes
* Linear scan queries

Designed for embedded, ephemeral, test, cache, and control-plane use cases.

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ISC.

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Created by Vidar Eldøy