Quickstart: Use .NET (C#) to query a database
Applies to:
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
In this quickstart, you'll use .NET and C# code to connect to a database. You'll then run a Transact-SQL statement to query data. This quickstart is applicable to Windows, Linux, and macOS and leverages the unified .NET platform.
Tip
This free Learn module shows you how to Develop and configure an ASP.NET application that queries a database in Azure SQL Database
Prerequisites
To complete this quickstart, you need:
An Azure account with an active subscription. Create an account for free.
.NET SDK for your operating system installed.
A database where you can run your query.
You can use one of these quickstarts to create and then configure a database:
Action SQL Database SQL Managed Instance SQL Server on Azure VM Azure Synapse Analytics Create Portal Portal Portal Portal CLI CLI PowerShell PowerShell PowerShell PowerShell Deployment template Deployment template Deployment template Deployment template Configure Server-level IP firewall rule Connectivity from a VM Connectivity settings Connectivity from on-premises Connect to a SQL Server instance Get connection information Azure SQL Azure SQL SQL VM Synapse SQL
Create a new .NET project
Open a command prompt and create a folder named sqltest. Navigate to this folder and run this command.
dotnet new console
This command creates new app project files, including an initial C# code file (Program.cs), an XML configuration file (sqltest.csproj), and needed binaries.
At the command prompt used above, run this command.
dotnet add package Microsoft.Data.SqlClient
This command adds the
Microsoft.Data.SqlClient
package to the project.
Insert code to query the database in Azure SQL Database
In a text editor such as Visual Studio Code, open Program.cs.
Replace the contents with the following code and add the appropriate values for your server, database, username, and password.
Note
To use an ADO.NET connection string, replace the 4 lines in the code setting the server, database, username, and password with the line below. In the string, set your username and password.
builder.ConnectionString="<your_ado_net_connection_string>";
using Microsoft.Data.SqlClient;
namespace sqltest
{
class Program
{
static void Main(string[] args)
{
try
{
SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder();
builder.DataSource = "<your_server.database.windows.net>";
builder.UserID = "<your_username>";
builder.Password = "<your_password>";
builder.InitialCatalog = "<your_database>";
using (SqlConnection connection = new SqlConnection(builder.ConnectionString))
{
Console.WriteLine("\nQuery data example:");
Console.WriteLine("=========================================\n");
connection.Open();
String sql = "SELECT name, collation_name FROM sys.databases";
using (SqlCommand command = new SqlCommand(sql, connection))
{
using (SqlDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine("{0} {1}", reader.GetString(0), reader.GetString(1));
}
}
}
}
}
catch (SqlException e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nDone. Press enter.");
Console.ReadLine();
}
}
}
Run the code
At the prompt, run the following commands.
dotnet restore dotnet run
Verify that the rows are returned, your output may include other values.
Query data example: ========================================= master SQL_Latin1_General_CP1_CI_AS tempdb SQL_Latin1_General_CP1_CI_AS WideWorldImporters Latin1_General_100_CI_AS Done. Press enter.
Choose Enter to close the application window.
Next steps
- Tutorial: Create a .NET console application using Visual Studio Code.
- Learn how to connect to Azure SQL Database using Azure Data Studio on Windows/Linux/macOS.
- Learn more about developing with .NET and SQL.
- Learn how to connect and query Azure SQL Database or Azure SQL Managed Instance, by using .NET in Visual Studio.
- Learn how to Design your first database with SSMS.
- For more information about .NET, see .NET documentation.