Develop C# Apps

AttentionThis page documents an earlier version. Go to the latest (v2.1)version.

• Cassandra
• Redis

Pre-requisites

This tutorial assumes that you have:

• installed YugabyteDB, created a universe and are able to interact with it using the CQL shell. If not, please follow these steps in the quick start guide.
• installed Visual Studio

Writing a HelloWorld C# app

In your Visual Studio create a new Project and choose Console Application as template. Follow the instructions to save the project.

Install Cassandra C# driver

To install the driver in your Visual Studio project

• Open your Project Solution View.
• Right-click on Packages and click Add Packages.
• Search for CassandraCSharpDriver and click Add Package.

Copy the contents below to your Program.cs file.

using System;
using System.Linq;
using Cassandra;
namespace Yugabyte_CSharp_Demo
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                var cluster = Cluster.Builder()
                                     .AddContactPoints("127.0.0.1")
                                     .WithPort(9042)
                                     .Build();
                var session = cluster.Connect();
                session.Execute("CREATE KEYSPACE IF NOT EXISTS ybdemo");
                Console.WriteLine("Created keyspace ybdemo");
                var createStmt = "CREATE TABLE IF NOT EXISTS ybdemo.employee(" +
                    "id int PRIMARY KEY, name varchar, age int, language varchar)";
                session.Execute(createStmt);
                Console.WriteLine("Created keyspace employee");
                var insertStmt = "INSERT INTO ybdemo.employee(id, name, age, language) " +
                    "VALUES (1, 'John', 35, 'C#')";
                session.Execute(insertStmt);
                Console.WriteLine("Inserted data: {0}", insertStmt);
                var preparedStmt = session.Prepare("SELECT name, age, language " +
                                                   "FROM ybdemo.employee WHERE id = ?");
                var selectStmt = preparedStmt.Bind(1);
                var result = session.Execute(selectStmt);
                var rows = result.GetRows().ToList();
                Console.WriteLine("Select query returned {0} rows", rows.Count());
                Console.WriteLine("Name\tAge\tLanguage");
                foreach (Row row in rows)
                    Console.WriteLine("{0}\t{1}\t{2}", row["name"], row["age"], row["language"]);
                session.Dispose();
                cluster.Dispose();
            }
            catch (Cassandra.NoHostAvailableException)
            {
                Console.WriteLine("Make sure YugabyteDB is running locally!.");
            }
            catch (Cassandra.InvalidQueryException ie)
            {
                Console.WriteLine("Invalid Query: " + ie.Message);
            }
        }
    }
}

Running the C# app

Run the C# app from menu select Run -> Start Without Debugging

You should see the following as the output.

Created keyspace ybdemo
Created keyspace employee
Inserted data: INSERT INTO ybdemo.employee(id, name, age, language) VALUES (1, 'John', 35, 'C#')
Select query returned 1 rows
Name    Age Language
John    35  C#

Pre-requisites

This tutorial assumes that you have:

• installed YugabyteDB, created a universe and are able to interact with it using the Redis shell. If not, please follow these steps in the quick start guide.
• installed Visual Studio

Writing a HelloWorld C# app

In your Visual Studio create a new Project and choose Console Application as template. Follow the instructions to save the project.

Install StackExchange.Redis C# driver

To install the driver in your Visual Studio project

• Open your Project Solution View.
• Right-click on Packages and click Add Packages.
• Search for StackExchange.Redis and click Add Package.

Copy the contents below to your Program.cs file.

using System;
using System.Collections.Generic;
using StackExchange.Redis;
namespace Yugabyte_CSharp_Demo
{
    class Program
    {
        static private void printHash(HashEntry[] hashes)
        {
            foreach (var hashEntry in hashes)
            {
                Console.WriteLine(string.Format("{0}: {1}", hashEntry.Name, hashEntry.Value));
            }
        }
        static void Main(string[] args)
        {
            try
            {
                ConfigurationOptions config = new ConfigurationOptions
                {
                    EndPoints =
                    {
                        { "127.0.0.1", 6379 },
                    },
                    CommandMap = CommandMap.Create(new HashSet<string>
                    {   // EXCLUDE commands that are not fully supported on Yugabyte side.
                        "SUBSCRIBE", "CLUSTER", "TIME", "PING"
                    }, available: false)
                };
                ConnectionMultiplexer connection = ConnectionMultiplexer.Connect(config);
                IDatabase redisDB = connection.GetDatabase();
                var hashKey = "1";
                HashEntry[] setHash = {
                  new HashEntry("name", "John"),
                  new HashEntry("age", 35),
                  new HashEntry("language", "C#"),
                  new HashEntry("client", "Redis")
                };
                Console.WriteLine("Successfully executed HMSET:");
                printHash(setHash);
                redisDB.HashSet(hashKey, setHash);
                var getHash = redisDB.HashGetAll(hashKey);
                Console.WriteLine("Successfully executed HMGET:");
                printHash(getHash);
            }
            catch (RedisConnectionException e)
            {
                Console.WriteLine("Unable to make a connection to local YugabyteDB. " +
                                  "Error:", e.Message);
            }
        }
    }
}

Running the C# app

Run the C# app from menu select Run -> Start Without Debugging

You should see the following as the output.

Successfully executed HMSET:
name: John
age: 35
language: C#
client: Redis
Successfully executed HMGET:
age: 35
client: Redis
language: C#
name: John