C# Drivers
Npgsql is an open source ADO.NET Data Provider for PostgreSQL; it allows programs written in C#, Visual Basic, and F# to access the YugabyteDB server.
Download the driver dependency
If you are using Visual Studio IDE, add the Npgsql package to your project as follows:
- Right-click Dependencies and choose Manage Nuget Packages
- Search for
Npgsql
and click Add Package
To add the Npgsql package to your project when not using an IDE, use the following dotnet
command:
dotnet add package Npgsql
or any of the other methods mentioned on the nuget page for Npgsql.
Fundamentals
Learn how to perform common tasks required for C# application development using the Npgsql driver.
Connect to YugabyteDB database
After setting up the dependencies, implement the C# client application that uses the Npgsql driver to connect to your YugabyteDB cluster and run a query on the sample data.
Import Npgsql and use the NpgsqlConnection
class to create the connection object to perform DDLs and DMLs against the database.
The following table describes the connection parameters for connecting to the YugabyteDB database.
Parameters | Description | Default |
---|---|---|
Host | Host name of the YugabyteDB instance | localhost |
Port | Listen port for YSQL | 5433 |
Database | Database name | yugabyte |
Username | User connecting to the database | yugabyte |
Password | Password for the user | yugabyte |
The following is a basic example connection string for connecting to YugabyteDB.
var connStringBuilder = "Host=localhost;Port=5433;Database=yugabyte;Username=yugabyte;Password=password"
NpgsqlConnection conn = new NpgsqlConnection(connStringBuilder);
Create table
Tables can be created in YugabyteDB by passing the CREATE TABLE
DDL statement to the NpgsqlCommand
class and getting a command object, then calling the ExecuteNonQuery()
method using this command object.
CREATE TABLE employee (id int PRIMARY KEY, name varchar, age int, language varchar)
conn.Open();
NpgsqlCommand empCreateCmd = new NpgsqlCommand("CREATE TABLE employee (id int PRIMARY KEY, name varchar, age int, language varchar);", conn);
empCreateCmd.ExecuteNonQuery();
Read and write data
Insert data
To write data into YugabyteDB, execute the INSERT
statement using the NpgsqlCommand
class, get a command object, and then call the ExecuteNonQuery()
method using this command object.
INSERT INTO employee (id, name, age, language) VALUES (1, 'John', 35, 'CSharp');
NpgsqlCommand empInsertCmd = new NpgsqlCommand("INSERT INTO employee (id, name, age, language) VALUES (1, 'John', 35, 'CSharp');", conn);
int numRows = empInsertCmd.ExecuteNonQuery();
Query data
To query data from YugabyteDB tables, execute the SELECT
statement using the NpgsqlCommand
class, get a command object, and then call the ExecuteReader()
function using the object. Loop through the reader to get the list of returned rows.
SELECT * from employee where id=1;
NpgsqlCommand empPrepCmd = new NpgsqlCommand("SELECT name, age, language FROM employee WHERE id = @EmployeeId", conn);
empPrepCmd.Parameters.Add("@EmployeeId", NpgsqlTypes.NpgsqlDbType.Integer);
empPrepCmd.Parameters["@EmployeeId"].Value = 1;
NpgsqlDataReader reader = empPrepCmd.ExecuteReader();
Console.WriteLine("Query returned:\nName\tAge\tLanguage");
while (reader.Read())
{
Console.WriteLine("{0}\t{1}\t{2}", reader.GetString(0), reader.GetInt32(1), reader.GetString(2));
}
Configure SSL/TLS
The following table describes the additional parameters the .NET Npgsql driver requires as part of the connection string when using SSL.
Npgsql Parameter | Description |
---|---|
SslMode | SSL Mode |
RootCertificate | Path to the root certificate on your computer |
TrustServerCertificate | For use with the Require SSL mode |
Npgsql supports SSL modes in different ways depending on the driver version, as shown in the following table.
SSL mode | Versions before 6.0 | Version 6.0 or later |
---|---|---|
Disable | Supported (default) | Supported |
Allow | Not Supported | Supported |
Prefer | Supported | Supported (default) |
Require | Supported For self-signed certificates, set TrustServerCertificate to true |
Supported Set TrustServerCertificate to true |
VerifyCA | Not Supported - use Require | Supported |
VerifyFull | Not Supported - use Require | Supported |
The .NET Npgsql driver validates certificates differently from other PostgreSQL drivers as follows:
-
Prior to version 6.0, when you specify SSL mode
Require
, you also need to specifyRootCertificate
, and the driver verifies the certificate by default (like the verify CA or verify full modes on other drivers), and fails for self-signed certificates.To use self-signed certificates, specify
TrustServerCertificate=true
, which bypasses walking the certificate chain to validate trust and hence works like other drivers' require mode. In this case, you don't need to specify theRootCertificate
. -
For version 6.0 and later, the
Require
SSL mode requires explicitly setting theTrustServerCertificate
field to true.
The following example shows how to build a connection string for connecting to a YugabyteDB cluster using the Require
SSL mode.
var connStringBuilder = new NpgsqlConnectionStringBuilder();
connStringBuilder.Host = "22420e3a-768b-43da-8dcb-xxxxxx.aws.ybdb.io";
connStringBuilder.Port = 5433;
connStringBuilder.SslMode = SslMode.Require;
connStringBuilder.Username = "admin";
connStringBuilder.Password = "xxxxxx";
connStringBuilder.Database = "yugabyte";
connStringBuilder.TrustServerCertificate = true;
CRUD(connStringBuilder.ConnectionString);
The following example shows how to build a connection string for connecting to a YugabyteDB cluster using the VerifyCA
and VerifyFull
SSL modes.
var connStringBuilder = new NpgsqlConnectionStringBuilder();
connStringBuilder.Host = "22420e3a-768b-43da-8dcb-xxxxxx.aws.ybdb.io";
connStringBuilder.Port = 5433;
connStringBuilder.SslMode = SslMode.VerifyCA;
//or connStringBuilder.SslMode = SslMode.VerifyFull;
connStringBuilder.RootCertificate = "/root.crt"; //Provide full path to your root CA.
connStringBuilder.Username = "admin";
connStringBuilder.Password = "xxxxxx";
connStringBuilder.Database = "yugabyte";
CRUD(connStringBuilder.ConnectionString);
For more information on TLS/SSL support, see Security and Encryption in the Npgsql documentation.
Compatibility matrix
Driver Version | YugabyteDB Version | Support |
---|---|---|
6.0.3 | 2.11 (preview) | full |
6.0.3 | 2.8 (stable) | full |
6.0.3 | 2.6 | full |