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Getting Started

Welcome to RavenDB!

This article will get you started and guide you through all the parts of RavenDB needed for basic understanding and simple setup. It consists of two parts:

  • The Server part will focus on installation, setup & configuration of the RavenDB server
  • The Client part will describe the general principles behind our client libraries

Server

Let's start by installing and configuring the server. In order to do that first we need to download the server package from the downloads page.

RavenDB is cross-platform with support for the following operating systems:

  • Windows x64 / x86
  • Linux x64
  • Docker
  • MacOS
  • Raspberry Pi

Prerequisites

RavenDB is written in .NET Core so it requires the same set of prerequisites as .NET Core.

Windows

Please install Visual C++ 2015 Redistributable Package (or newer) before launching the RavenDB server. This package should be the sole requirement for 'Windows' platforms. If you're experiencing difficulties, please check the Prerequisites for .NET Core on Windows article written by Microsoft.

Linux

We highly recommend updating your Linux OS prior to launching the RavenDB server. Also check if .NET Core requires any other prerequisites in the Prerequisites for .NET Core on Linux article written by Microsoft.

MacOS

We highly recommend updating your MacOS and checking the Prerequisites for .NET Core on macOS article written by Microsoft before launching the RavenDB Server.


Installation & Setup

After extraction of the server package, you can start the Setup Wizard by running the run.ps1 (or run.sh) script or by disabling the 'Setup Wizard' and configuring the server manually.

Running in a Docker container

If you are interested in hosting the server in a Docker container, please read our dedicated article.


Configuration

The RavenDB server is using a settings.json file to store the server-wide configuration options. This file is located in the Server directory, but please note that after making changes to this file, a server restart is required in order for them to be applied.

You can read more about the available configuration options in our dedicated article.

Default configuration

The configuration file included in each RavenDB server distribution package is as follows:

{
    "ServerUrl": "http://127.0.0.1:0",
    "Setup.Mode": "Initial",
    "DataDir": "RavenData"
}

Which means that the server will run:

  • On localhost with a random port
  • In Setup Wizard mode
  • Store the data in the RavenData directory.

Port in Use

In some cases the port might be in use. This will prevent the Server from starting with an "address in use" error (EADDRINUSE).

The port can be changed by editing the ServerUrl value.

Write Permissions

RavenDB requires write permissions to the following locations:

If you intend to run as a service, the write permissions should be granted to the user running the service (e.g. "Local Service").


Studio

Free

Our GUI, the RavenDB Management Studio, comes free with every license type:

  • Community
  • Professional
  • Enterprise

After installation and setup, the Studio can be accessed via the browser using the ServerUrl or the ServerPublicUrl value e.g. http://localhost:8080.


Security Concerns

To let a developer start coding an application quickly, RavenDB will run with the following default security mode:

Default Security Mode

As long as the database is used inside the local machine and no outside connections are allowed, you can ignore security concerns and you require no authentication. Once you set RavenDB to listen to connections outside your local machine, your database will immediately block this now vulnerable configuration and require the administrator to properly setup the security and access control to prevent unauthorized access to your data or to explicitly allow the unsecured configuration.

We recommend using the 'Setup Wizard' to easily install RavenDB securely from the very start.

Read more about security and how to enable authentication here.

Client

After your server is up and running, to write an application you need to acquire one of the Client access libraries:


DocumentStore

In order to start, you need to create an instance of the DocumentStore - the main entry point for your application which is responsible for establishing and managing connections between a RavenDB server (or cluster) and your application.

Examples

Before proceeding to the examples, we would like to point out that most of the articles are using the Northwind database. You can read more about it and how to deploy it here.

using (IDocumentStore store = new DocumentStore
{
    Urls = new[]                        // URL to the Server,
    {                                   // or list of URLs 
        "http://live-test.ravendb.net"  // to all Cluster Servers (Nodes)
    },
    Database = "Northwind",             // Default database that DocumentStore will interact with
    Conventions = { }                   // DocumentStore customizations
})
{
    store.Initialize();                 // Each DocumentStore needs to be initialized before use.
                                        // This process establishes the connection with the Server
                                        // and downloads various configurations
                                        // e.g. cluster topology or client configuration
}
try (IDocumentStore store = new DocumentStore(
    new String[]{ "http://live-test.ravendb.net" },        // URL to the Server,
    // or list of URLs
    // to all Cluster Servers (Nodes)
    "Northwind")                                           // Default database that DocumentStore will interact with
) {

    DocumentConventions conventions = store.getConventions();  // DocumentStore customizations

    store.initialize();                                        // Each DocumentStore needs to be initialized before use.
    // This process establishes the connection with the Server
    // and downloads various configurations
    // e.g. cluster topology or client configuration
}
const { DocumentStore } = require('ravendb');

const store = DocumentStore.create(
    ['http://live-test.ravendb.net'],   // URL to the Server
                                        // or list of URLs
                                        // to all Cluster Servers (Nodes)

    'Northwind');                       // Default database that DocumentStore will interact with

const conventions = store.conventions;  // DocumentStore customizations

store.initialize();                     // Each DocumentStore needs to be initialized before use.
                                        // This process establishes the connection with the Server
                                        // and downloads various configurations
                                        // e.g. cluster topology or client configuration

await store.dispose();                  // Dispose the resources claimed by the DocumentStore
from pyravendb.store import document_store

with document_store.DocumentStore(
    urls=["http://live-test.ravendb.net"],  # URL to the Server
                                            # or list of URLs
                                            # to all Cluster Servers (Nodes)

    database="Northwind") as store:         # Default database that DocumentStore will interact with
    
    conventions = store.conventions         # DocumentStore customizations
    
    store.initialize()                      # Each DocumentStore needs to be initialized before use.
                                            # This process establishes the connection with the Server
                                            # and downloads various configurations
                                            # e.g. cluster topology or client configuration

Singleton

The DocumentStore is capable of working with multiple databases and for proper operation we recommend having only one instance of it per application.

The following articles can extend your knowledge about the DocumentStore and its configuration:


Session

The Session is used to manipulate the data. It implements the Unit of Work pattern and is capable of batching the requests to save expensive remote calls. In contrast to a DocumentStore it is a lightweight object and can be created more frequently. For example, in web applications, a common (and recommended) pattern is to create a session per request.

Example I - Storing

RavenDB is a Document Database. All stored objects are called documents. Each document contains a unique ID that identifies it, data and adjacent metadata, both stored in JSON format. The metadata contains information describing the document, e.g. the last modification date (@last-modified property) or the collection (@collection property) assignment.

using (IDocumentSession session = store.OpenSession())  // Open a session for a default 'Database'
{
    Category category = new Category
    {
        Name = "Database Category"
    };

    session.Store(category);                            // Assign an 'Id' and collection (Categories)
                                                        // and start tracking an entity

    Product product = new Product
    {
        Name = "RavenDB Database",
        Category = category.Id,
        UnitsInStock = 10
    };

    session.Store(product);                             // Assign an 'Id' and collection (Products)
                                                        // and start tracking an entity

    session.SaveChanges();                              // Send to the Server
                                                        // one request processed in one transaction
}
try (IDocumentSession session = store.openSession()) {      // Open a session for a default 'Database'
    Category category = new Category();
    category.setName("Database Category");

    session.store(category);                            // Assign an 'Id' and collection (Categories)
    // and start tracking an entity

    Product product = new Product();
    product.setName("RavenDB Database");
    product.setCategory(category.getId());
    product.setUnitsInStock(10);

    session.store(product);                             // Assign an 'Id' and collection (Products)
    // and start tracking an entity

    session.saveChanges();                              // Send to the Server
    // one request processed in one transaction
}
const session = store.openSession();                // Open a session for a default 'Database'

let category = new Category("Database Category");

await session.store(category);                      // Assign an 'Id' and collection (Categories)
                                                    // and start tracking an entity

let product = new Product(
    "RavenDB Database",
    category.Id, 
    10);

await session.store(product);                       // Assign an 'Id' and collection (Products)
                                                    // and start tracking an entity

await session.saveChanges();                        // Send to the Server
                                                    // one request processed in one transaction
with store.open_session() as session:           # Open a session for a default 'Database'
    category = Category("Database Category")
    
    session.store(category)                     # Assign an 'Id' and collection (Categories)
                                                # and start tracking an entity

    product = Product(
        "RavenDB Database", 
        category.Id, 
        10)

    session.store(product)                      # Assign an 'Id' and collection (Products)
                                                # and start tracking an entity

    session.save_changes()                      # Send to the Server
                                                # one request processed in one transaction

Example II - Loading

The Session was designed to help the user write efficient code easily. For example, when a document is being loaded (.Load) from the server, there is an option to retrieve additional documents in the same request (using .Include), keeping the number of expensive calls to minimum.

Besides that, the session implements the Unit of Work pattern, meaning that all changes to loaded entities are automatically tracked. The SaveChanges call will synchronize (with the server) only the documents that have changed within the session. All of those changes are sent in one request (saving network calls) and processed in one transaction (you can read why RavenDB is an ACID database here).

using (IDocumentSession session = store.OpenSession())  // Open a session for a default 'Database'
{
    Product product = session
        .Include<Product>(x => x.Category)              // Include Category
        .Load(productId);                               // Load the Product and start tracking

    Category category = session
        .Load<Category>(product.Category);              // No remote calls,
                                                        // Session contains this entity from .Include

    product.Name = "RavenDB";                           // Apply changes
    category.Name = "Database";

    session.SaveChanges();                              // Synchronize with the Server
                                                        // one request processed in one transaction
}
try (IDocumentSession session = store.openSession()) {     // Open a session for a default 'Database'
    Product product = session
        .include("category")                        // Include Category
        .load(Product.class, productId);            // Load the Product and start tracking

    Category category = session
        .load(Category.class,                       // No remote calls,
            product.getCategory());             // Session contains this entity from .include

    product.setName("RavenDB");                         // Apply changes
    category.setName("Database");


    session.saveChanges();                              // Synchronize with the Server
    // one request processed in one transaction
}
const session = store.openSession();                // Open a session for a default 'Database'

let product = await session
    .include('Category')                            // Include Category
    .load(productId)                                // Load the Product and start tracking

let category = await session
    .load(product.Category);                        // No remote calls,
                                                    // Session contains this entity from .include

product.Name = 'RavenDB';                           // Apply changes
category.Name = 'Database';

await session.saveChanges();                        // Synchronize with the Server
                                                    // one request processed in one transaction
with store.open_session() as session:           # Open a session for a default 'Database'

    product = session
        .include("Category")                    # Include Category
        .load(product_id, object_type=Product)  # Load the Product and start tracking

    category = session.load(                    # No remote calls,
        product.Category,                       # Session contains this entity from .include
        object_type=Category)

    product.Name = "RavenDB"                    # Apply changes
    category.Name = "Database"

    session.save_changes()                      # Synchronize with the Server
                                                # one request processed in one transaction

Example III - Querying

To satisfy queries, indexes are used. From the querying perspective, an index defines which document fields can be used to find a document. The whole indexing process is done asynchronously, which gives very quick querying response times, even when large amounts of data have been changed. However, an implication of this approach is that the index might be stale.

When no index is specified in the query (like in the query below), RavenDB will use its intelligent auto-indexes feature that will either use an already existing index or create a new one if no match is found. The other option is to write the index yourself and deploy it to the server. Those indexes are called Static Indexes.

Behind the scenes, queries are translated to the Raven Query Language (RQL) syntax. Read more about RQL here.

using (IDocumentSession session = store.OpenSession())  // Open a session for a default 'Database'
{
    List<string> productNames = session
        .Query<Product>()                               // Query for Products
        .Where(x => x.UnitsInStock > 5)                 // Filter
        .Skip(0).Take(10)                               // Page
        .Select(x => x.Name)                            // Project
        .ToList();                                      // Materialize query
}
try (IDocumentSession session = store.openSession()) {      // Open a session for a default 'Database'
    List<String> productNames = session
        .query(Product.class)                       // Query for Products
        .whereGreaterThan("unitsInStock", 5)        // Filter
        .skip(0).take(10)                           // Page
        .selectFields(String.class, "name")         // Project
        .toList();                                  // Materialize query
}
const session = store.openSession();                // Open a session for a default 'Database'

let productNames = await session
    .query({ collection: 'Products' })              // Query for Products
    .whereGreaterThan('UnitsInStock', 5)            // Filter
    .skip(0).take(10)                               // Page
    .selectFields(["Name"])                         // Project
    .all();                                         // Materialize query
with store.open_session() as session:               # Open a session for a default 'Database'

    productNames = list(                            # Materialize query
        session
            .query(object_type=Product)             # Query for Products
            .where_greater_than("UnitsInStock", 5)  # Filter
            .skip(0).take(10)                       # Page
            .select("Name")                         # Project
    )
from Products
where UnitsInStock > 5
select Name

The following articles can extend your knowledge about the Session:

The introductory articles describing Querying can be found here:

If you wish to understand Indexes better, we recommend reading the following articles: