QuickBooks Online is a cloud-based financial management solution designed for invoicing, expense tracking, and financial reporting tasks. It is a popular solution for businesses that seek better accessibility to accounting data and real-time collaboration. However, reliable and efficient connectivity becomes essential for retrieving and modifying data when third-party or integrated applications use QuickBooks Online as a data source.
One effective solution is dotConnect for QuickBooks Online, a data provider with built-in support for Entity Framework Core. It addresses common connectivity challenges and simplifies data access. In this article, we'll demonstrate how to connect to QuickBooks Online using EF Core and dotConnect, build a C# project, and perform everyday data operations.
dotConnect makes it easy for .NET applications to connect to QuickBooks Online and access accounting data like customers, invoices, and payments without dealing with API complexity.
dotConnect supports authentication via Interactive OAuth with a browser-based login flow for users. After authorization, it automatically obtains and manages access and refresh tokens.
The data provider uses standard ADO.NET data access classes, letting developers interact with QuickBooks Online data using familiar connection, command, and data reader patterns.
dotConnect supports popular .NET ORM technologies, including EF Core, Dapper, NHibernate, and LinqConnect, for QuickBooks Online data modeling.
Established ADO.NET interfaces and conventions ensure reliable integration with existing .NET applications and development workflows.
Dedicated technical support, comprehensive documentation, and regular updates ensure compatibility with QuickBooks Online services and .NET platforms.
You can start using dotConnect for QuickBooks Online immediately with a 30-day free trial. Choose one of the following installation options:
In the Server Explorer, right-click Data Connections and select Add Connection...
In the Choose Data Source window, select dotConnect for QuickBooks from the list of installed data providers. Click Continue.
In the Add Connection window, click Web login and enter the Company ID and Access Token.
Click Test Connection to verify the connection settings. Now you can connect to QuickBooks Online.
Expand the newly created data connection to view the database structure in the Server Explorer. Then expand the Tables node to see a list of tables in the database. Further expand any table to view its columns.
To fetch data from a table, right-click the table name and select Retrieve Data from Table. A query window opens with a SELECT statement to retrieve the necessary data portion from the table.
After configuring the database, the next stage is to create an EF Core model. You can do this in two ways: with Scaffold-DbContext or via Entity Developer.
Check the EF Core Tools that you need to have installed. To install them globally, run the following command in the .NET command-line interface (CLI):
Install Scaffold-DbContext using Package Manager Console. In Visual Studio, go to Tools > NuGet Package Manager > Package Manager Console and run the following command:
When the package is installed, you can use Scaffold-DbContext to generate DbContext and entity classes. Run the command below in the Package Manager Console, replacing values with your actual credentials:
Scaffold-DbContext "Authentication Type=OAuthInteractive;License Key=************;" -provider Devart.Data.QuickBooks.EFCore -OutputDir ModelsThis command generates the ModelContext file and the Models folder that contains the table entity classes, which you will see in the Solution Explorer. Now, the DbContext classes are successfully created.
The following table lists the valid names for values within the QuickBooks Online connection strings.
| Name | Description |
|---|---|
| Authentication Type | Authentication method to use. The supported types are Refresh Token, Access Token, and OAuthInteractive |
| Company Id | Unique identifier for a QuickBooks company |
| Access Token | QuickBooks OAuth 2.0 access token |
| Client Id | One of the two OAuth 2.0 credentials obtained when the application is registered |
| Client Secret | The second part of the two OAuth 2.0 credentials |
| License Key | License key that should be specified in the connection string |
For the full list of available connection string parameters, see Connection string parameters reference .
Another approach to creating EF Core models is with the help of Entity Developer, a powerful ORM designer with both the model-first and database-first approaches, excellent visualization, and flawless integration with Visual Studio.
Follow the detailed illustrated guide to create your database model using Entity Developer. When this process is complete, it will open the model you created.
The DbContext class is successfully created as well.
Now, we can proceed to performing data-related operations in our application.
This tutorial assumes that the Customer table with data exists in your QuickBooks Online account. Adjust the field names and data types as necessary to match your actual data model, and use the following code to retrieve data from QuickBooks Online into your application.
using(var context = new QbModel()) {
try {
var customers = context.Customers
.Select(c => new {
DisplayName = c.DisplayName, // Use DisplayName instead of FullyQualifiedName
CompanyName = c.CompanyName,
PrimaryEmailAddrAddress = c.PrimaryEmailAddrAddress
})
.Take(10) // Limit the results to 10 customers
.ToList();
foreach(var customer in customers) {
Console.WriteLine($"Display Name: {customer.DisplayName}");
Console.WriteLine($"Company Name: {customer.CompanyName}");
Console.WriteLine($"Email: {customer.PrimaryEmailAddrAddress}");
Console.WriteLine(new string('-', 20));
}
} catch (Exception ex) {
Console.WriteLine($"An error occurred: {ex.Message}");
}
}You can see the data from the DisplayName, CompanyName, and PrimaryEmailAddrAddress fields retrieved and displayed for each customer successfully.
In most applications, a common scenario involves inserting records into a database and displaying the results. The example below demonstrates how to add records and retrieve the updated data.
using(var context = new QbModel()) {
try {
// Check connection status
var canConnect = context.Database.CanConnect();
if (canConnect) {
Console.WriteLine("Connection to QuickBooks Online was successful.");
}
else {
Console.WriteLine("Failed to connect to QuickBooks Online.");
return;
}
// Insert 5 new Customer records
var newCustomers = new [] {
new Customer {
DisplayName = "Customer 1",
CompanyName = "Company A",
PrimaryEmailAddrAddress = "customer1@@example.com"
},
new Customer {
DisplayName = "Customer 2",
CompanyName = "Company B",
PrimaryEmailAddrAddress = "customer2@@example.com"
},
new Customer {
DisplayName = "Customer 3",
CompanyName = "Company C",
PrimaryEmailAddrAddress = "customer3@@example.com"
},
new Customer {
DisplayName = "Customer 4",
CompanyName = "Company D",
PrimaryEmailAddrAddress = "customer4@@example.com"
},
new Customer {
DisplayName = "Customer 5",
CompanyName = "Company E",
PrimaryEmailAddrAddress = "customer5@@example.com"
}
};
context.Customers.AddRange(newCustomers);
context.SaveChanges();
Console.WriteLine("5 new customer records inserted successfully.");
// Retrieve and display the inserted records
var insertedCustomers = context.Customers
.Where(c =>
newCustomers.Select(nc => nc.DisplayName)
.Contains(c.DisplayName))
.Select(c => new {
DisplayName = c.DisplayName,
CompanyName = c.CompanyName,
PrimaryEmailAddrAddress = c.PrimaryEmailAddrAddress
})
.ToList();
foreach(var customer in insertedCustomers) {
Console.WriteLine($"Display Name: {customer.DisplayName}");
Console.WriteLine($"Company Name: {customer.CompanyName}");
Console.WriteLine($"Email: {customer.PrimaryEmailAddrAddress}");
Console.WriteLine(new string('-', 20));
}
}
catch (Exception ex) {
Console.WriteLine($"An error occurred: {ex.Message}");
}
}This way, we have created and added five new customer records to the Customers DbSet using the AddRange method. The SaveChanges method is called to push these changes to the database.
We can see the new data in the application:
Let's update the existing records with DisplayName values Customer 1, Customer 2, and so on. We need to modify the DisplayName and CompanyName fields.
using(var context = new QbModel()) {
try {
// Check connection status
var canConnect = context.Database.CanConnect();
if (canConnect) {
Console.WriteLine("Connection to QuickBooks Online was successful.");
}
else {
Console.WriteLine("Failed to connect to QuickBooks Online.");
return;
}
// Update the specific records
var customersToUpdate = context.Customers
.Where(c => new [] {
"Customer 1",
"Customer 2",
"Customer 3",
"Customer 4",
"Customer 5"
}
.Contains(c.DisplayName))
.ToList();
foreach(var customer in customersToUpdate) {
customer.DisplayName = $"{customer.DisplayName} Updated";
customer.CompanyName = $"{customer.CompanyName} Updated";
}
context.SaveChanges();
Console.WriteLine("Customer records updated successfully.");
// Retrieve and display the updated records
var updatedCustomers = context.Customers
.Where(c => new [] {
"Customer 1 Updated",
"Customer 2 Updated",
"Customer 3 Updated",
"Customer 4 Updated",
"Customer 5 Updated"
}
.Contains(c.DisplayName))
.Select(c => new {
DisplayName = c.DisplayName,
CompanyName = c.CompanyName,
PrimaryEmailAddrAddress = c.PrimaryEmailAddrAddress
})
.ToList();
foreach(var customer in updatedCustomers) {
Console.WriteLine($"Display Name: {customer.DisplayName}");
Console.WriteLine($"Company Name: {customer.CompanyName}");
Console.WriteLine($"Email: {customer.PrimaryEmailAddrAddress}");
Console.WriteLine(new string('-', 20));
}
}
catch (Exception ex) {
Console.WriteLine($"An error occurred: {ex.Message}");
}
}We filter the records by using the Updated value in the DisplayName and CompanyName fields. Call the SaveChanges method to save the updates in the database.
Assume we need to delete the last added records from the database. For that, we use the RemoveRange method.
Modify the Program.cs as shown below:
using(var context = new QbModel()) {
try {
// Check connection status
var canConnect = context.Database.CanConnect();
if (canConnect) {
Console.WriteLine("Connection to QuickBooks Online was successful.");
}
else {
Console.WriteLine("Failed to connect to QuickBooks Online.");
return;
}
// Find and delete the specific records
var customersToDelete = context.Customers
.Where(c => new [] {
"Customer 1 Updated",
"Customer 2 Updated",
"Customer 3 Updated",
"Customer 4 Updated",
"Customer 5 Updated"
}
.Contains(c.DisplayName))
.ToList();
context.Customers.RemoveRange(customersToDelete);
context.SaveChanges();
Console.WriteLine("Customer records deleted successfully.");
// Optionally, verify deletion by attempting to retrieve the deleted records
var deletedCustomers = context.Customers
.Where(c => new [] {
"Customer 1 Updated",
"Customer 2 Updated",
"Customer 3 Updated",
"Customer 4 Updated",
"Customer 5 Updated"
}
.Contains(c.DisplayName))
.ToList();
if (!deletedCustomers.Any()) {
Console.WriteLine("Verified: The specified customer records have been deleted.");
}
else {
Console.WriteLine("Some records were not deleted.");
}
}
catch (Exception ex) {
Console.WriteLine($"An error occurred: {ex.Message}");
}
}When we execute this code, it deletes specified customer records and verifies the results.
Using QuickBooks Online as a data source for C# applications is a popular choice. However, the effectiveness of any application depends on reliable data connectivity, ensuring correct connections and easy access to retrieve, update, and manage data stored in that source.
dotConnect for QuickBooks Online provides a direct connection to this cloud service without additional clients or libraries. It enables you to develop C# applications using ADO.NET and EF Core, delivering fast, stable, and smooth data access.
You can try dotConnect for QuickBooks Online with a fully functional 30-day trial, letting you test its features in real-world scenarios under actual workload. To help you get started as quickly and easily as possible, we suggest you refer to the documentation, which is replete with useful tips and walkthroughs.
Authentication Type=OAuthInteractive
I'm a technical content writer who loves turning complex topics — think SQL, connectors, and backend chaos–into content that actually makes sense (and maybe even makes you smile). I write for devs, data folks, and curious minds who want less fluff and more clarity. When I'm not wrangling words, you'll find me dancing salsa, or hopping between cities.
