add cshar page

Author: mshustov

docs/integrations/language-clients/csharp.md

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+---
+sidebar_label: 'C#'
+sidebar_position: 6
+keywords: ['clickhouse', 'cs', 'c#', '.net', 'dotnet', 'csharp', 'client', 'driver', 'connect', 'integrate']
+slug: /integrations/csharp
+description: 'The official C# client for connecting to ClickHouse.'
+title: 'ClickHouse C# Driver'
+---
+
+# ClickHouse C# Client
+
+The official C# client for connecting to ClickHouse. 
+The client source code is available in the [GitHub repository](https://github.com/ClickHouse/clickhouse-cs).
+Originally developed by [Oleg V. Kozlyuk](https://github.com/DarkWanderer).
+
+## Supported .NET Versions {#supported-net-versions}
+
+`ClickHouse.Driver` supports the following .NET versions:
+* .NET Framework 4.6.2
+* .NET Framework 4.8
+* .NET Standard 2.1
+* .NET 6.0
+* .NET 8.0
+* .NET 9.0
+
+## Installation {#installation}
+
+Install the package from NuGet:
+
+```bash
+dotnet add package ClickHouse.Driver
+```
+
+Or using the NuGet Package Manager:
+
+```bash
+Install-Package ClickHouse.Driver
+```
+
+## Usage {#usage}
+
+### Creating a Connection {#creating-a-connection}
+
+Create a connection using a connection string:
+
+```csharp
+using ClickHouse.Driver.ADO;
+
+var connectionString = "Host=localhost;Protocol=http;Database=default;Username=default;Password=";
+
+using (var connection = new ClickHouseConnection(connectionString))
+{
+    connection.Open();
+}
+```
+
+### Creating a Table {#creating-a-table}
+
+Create a table using standard SQL syntax:
+
+```csharp
+using ClickHouse.Driver.ADO;
+
+using (var connection = new ClickHouseConnection(connectionString))
+{
+    connection.Open();
+
+    using (var command = connection.CreateCommand())
+    {
+        command.CommandText = "CREATE TABLE IF NOT EXISTS default.my_table (id Int64, name String) ENGINE = Memory";
+        command.ExecuteNonQuery();
+    }
+}
+```
+
+### Inserting Data {#inserting-data}
+
+Insert data using parameterized queries:
+
+```csharp
+using ClickHouse.Driver.ADO;
+
+using (var connection = new ClickHouseConnection(connectionString))
+{
+    connection.Open();
+
+    using (var command = connection.CreateCommand())
+    {
+        command.AddParameter("id", "Int64", 1);
+        command.AddParameter("name", "String", "test");
+        command.CommandText = "INSERT INTO default.my_table (id, name) VALUES ({id:Int64}, {name:String})";
+        command.ExecuteNonQuery();
+    }
+}
+```
+
+### Bulk Insert {#bulk-insert}
+
+```csharp
+using ClickHouse.Driver.ADO;
+using ClickHouse.Driver.Copy;
+
+using (var connection = new ClickHouseConnection(connectionString))
+{
+    connection.Open();
+
+    using var bulkInsert = new ClickHouseBulkCopy(connection)
+    {
+        DestinationTableName = "default.my_table",
+        MaxDegreeOfParallelism = 2,
+        BatchSize = 100
+    };
+    
+    var values = Enumerable.Range(0, 100).Select(i => new object[] { (long)i, "value" + i.ToString() });
+    await bulkInsert.WriteToServerAsync(values);
+    Console.WriteLine($"Rows written: {bulkInsert.RowsWritten}");
+}
+```
+
+### Performing SELECT Queries {#performing-select-queries}
+
+Execute SELECT queries and process results:
+
+```csharp
+using ClickHouse.Client.ADO;
+using System.Data;
+
+using (var connection = new ClickHouseConnection(connectionString))
+{
+    connection.Open();
+    
+    using (var command = connection.CreateCommand())
+    {
+        command.AddParameter("id", "Int64", 10);
+        command.CommandText = "SELECT * FROM default.my_table WHERE id < {id:Int64}";
+        using var reader = command.ExecuteReader();
+        while (reader.Read())
+        {
+            Console.WriteLine($"select: Id: {reader.GetInt64(0)}, Name: {reader.GetString(1)}");
+        }
+    }
+}
+```
+### Raw streaming {#raw-streaming}
+```csharp
+using var command = connection.CreateCommand();
+command.Text = "SELECT * FROM default.my_table LIMIT 100 FORMAT JSONEachRow";
+using var result = await command.ExecuteRawResultAsync(CancellationToken.None);
+using var stream = await result.ReadAsStreamAsync();
+using var reader = new StreamReader(stream);
+var json = reader.ReadToEnd();
+```
+
+## Supported Data Types {#supported-data-types}
+
+`ClickHouse.Driver` supports the following ClickHouse data types:
+**Boolean Type**
+* `Bool` (bool)
+
+**Numeric Types**:
+* `Int8` (sbyte)
+* `Int16` (short)
+* `Int32` (int)
+* `Int64` (long)
+* `Int128` (BigInteger)
+* `Int256` (BigInteger)
+* `UInt8` (byte)
+* `UInt16` (ushort)
+* `UInt32` (uint)
+* `UInt64` (ulong)
+* `UInt128` (BigInteger)
+* `UInt256` (BigInteger)
+* `Float32` (float)
+* `Float64` (double)
+* `Decimal` (decimal)
+* `Decimal32` (decimal)
+* `Decimal64` (decimal)
+* `Decimal256` (BigDecimal)
+
+**String Types**
+* `String` (string)
+* `FixedString` (string)
+
+**Date and Time Types**
+* `Date` (DateTime)
+* `Date32` (DateTime)
+* `DateTime` (DateTime)
+* `DateTime32` (DateTime)
+* `DateTime64` (DateTime)
+
+**Network Types**
+* `IPv4` (IPAddress)
+* `IPv6` (IPAddress)
+
+**Geo Types**
+* `Point` (Tuple)
+* `Ring` (Array of Points)
+* `Polygon` (Array of Rings)
+
+**Complex Types**
+* `Array` (Array of any type)
+* `Tuple` (Tuple of any types)
+* `Nullable` (Nullable version of any type)
+
+### DateTime handling {#datetime-handling}
+`ClickHouse.Driver` tries to correctly handle timezones and `DateTime.Kind` property. Specifically:
+
+`DateTime` values are returned as UTC. User can then convert them themselves or use `ToLocalTime()` method on `DateTime` instance.
+When inserting, `DateTime` values are handled in following way:
+- UTC `DateTime` are inserted as is, because ClickHouse stores them in UTC internally
+- Local `DateTime` are converted to UTC according to user's local timezone settings
+- Unspecified `DateTime` are considered to be in target column's timezone, and hence are converted to UTC according to that timezone