--- toc_max_heading_level: 4 sidebar_position: 7 sidebar_label: C# title: C# Connector --- import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem'; import Preparation from "./_preparation.mdx" import CSInsert from "../../07-develop/03-insert-data/_cs_sql.mdx" import CSInfluxLine from "../../07-develop/03-insert-data/_cs_line.mdx" import CSOpenTSDBTelnet from "../../07-develop/03-insert-data/_cs_opts_telnet.mdx" import CSOpenTSDBJson from "../../07-develop/03-insert-data/_cs_opts_json.mdx" import CSQuery from "../../07-develop/04-query-data/_cs.mdx" import CSAsyncQuery from "../../07-develop/04-query-data/_cs_async.mdx" `TDengine.Connector` is a C# language connector provided by TDengine that allows C# developers to develop C# applications that access TDengine cluster data. The `TDengine.Connector` connector supports connect to TDengine instances via the TDengine client driver (taosc), providing data writing, querying, subscription, schemaless writing, bind interface, etc. The `TDengine.Connector` currently does not provide a REST connection interface. Developers can write their RESTful application by referring to the [RESTful APIs](https://docs.taosdata.com//reference/restful-api/) documentation. This article describes how to install `TDengine.Connector` in a Linux or Windows environment and connect to TDengine clusters via `TDengine.Connector` to perform basic operations such as data writing and querying. The source code of `TDengine.Connector` is hosted on [GitHub](https://github.com/taosdata/taos-connector-dotnet). ## Supported Platforms The supported platforms are the same as those supported by the TDengine client driver. ## Version support Please refer to [version support list](/reference/connector#version-support) ## Supported features 1. Connection Management 2. General Query 3. Continuous Query 4. Parameter Binding 5. Subscription 6. Schemaless ## Installation Steps ### Pre-installation preparation * Install the [.NET SDK](https://dotnet.microsoft.com/download) * [Nuget Client](https://docs.microsoft.com/en-us/nuget/install-nuget-client-tools) (optional installation) * Install TDengine client driver, please refer to [Install client driver](/reference/connector#Install client driver) for details ### Install via dotnet CLI You can reference the `TDengine.Connector` published in Nuget to the current project via the `dotnet` command under the path of the existing .NET project. ``` bash dotnet add package TDengine.Connector ``` You can download TDengine's source code and directly reference the latest version of the TDengine.Connector library ```bash git clone https://github.com/taosdata/TDengine.git cd TDengine/src/connector/C#/src/ cp -r TDengineDriver/ myProject cd myProject dotnet add TDengineDriver/TDengineDriver.csproj ``` ## Create a connection ``` C# using TDengineDriver; namespace TDengineExample { internal class EstablishConnection { static void Main(String[] args) { string host = "localhost"; short port = 6030; string username = "root"; string password = "taosdata"; string dbname = ""; var conn = TDengine.Connect(host, username, password, dbname, port); if (conn == IntPtr.Zero) { Console.WriteLine("Connect to TDengine failed"); } else { Console.WriteLine("Connect to TDengine success"); } TDengine.Close(conn); TDengine.Cleanup(); } } } ``` ## Usage examples ### Write data #### SQL Write #### InfluxDB line protocol write #### OpenTSDB Telnet line protocol write #### OpenTSDB JSON line protocol write ### Query data #### Synchronous Query #### Asynchronous query ### More sample programs |Sample program |Sample program description | |--------------------------------------------------------------------------------------------------------------------|------------ --------------------------------| | [C#checker](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/C%23checker) | Using TDengine.Connector, you can test C# Driver's synchronous writes and queries | | [TDengineTest](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/TDengineTest) | A simple example of writing and querying using TDengine. | [insertCn](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/insertCn) | Example of writing and querying Chinese characters using TDengine. | [jsonTag](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/jsonTag) | Example of writing and querying JSON tag type data using TDengine. | [stmt](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/stmt) | Example of parameter binding using TDengine. | [schemaless](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/schemaless) | Example of writing with schemaless implemented using TDengine. |schemaless | [benchmark](https://github.com/taosdata/TDengine/tree/develop/examples/C%23/taosdemo) | A simple benchmark implemented using TDengine. | [async query](https://github.com/taosdata/taos-connector-dotnet/blob/develop/examples/QueryAsyncSample.cs) | Example of an asynchronous query implemented using TDengine. Example of an asynchronous query | [subscribe](https://github.com/taosdata/taos-connector-dotnet/blob/develop/examples/SubscribeSample.cs) | Example of subscribing to data using TDengine. Data example ## Important update records | TDengine.Connector | Description | |--------------------|--------------------------------| | 1.0.6 | Fix schemaless bug in 1.0.4 and 1.0.5. | | 1.0.5 | Fix Windows sync query Chinese error bug. | 1.0.4 | Fix schemaless bug. | 1.0.4 | Add asynchronous query, subscription, and other functions. Fix the binding parameter bug. | 1.0.3 | Add parameter binding, schemaless, JSON tag, etc. | new | 1.0.2 | Add connection management, synchronous query, error messages, etc. ## Other ## Other descriptions ### Third-party driver `Taos` is an ADO.NET connector for TDengine, supporting Linux and Windows platforms. Community contributor `Maikebing@@maikebing contributes the connector`. Please refer to: * Interface download: * Usage notes: ## Frequently Asked Questions 1. "Unable to establish connection", "Unable to resolve FQDN" Usually, it cause by the FQDN configuration is incorrect, you can refer to [How to understand TDengine's FQDN (Chinese)](https://www.taosdata.com/blog/2021/07/29/2741.html) to solve it. 2. Unhandled exception. System.DllNotFoundException: Unable to load DLL 'taos' or one of its dependencies: The specified module cannot be found. This is usually because the program did not find the dependent client driver. The solution is to copy `C:\TDengine\driver\taos.dll` to the `C:\Windows\System32\` directory on Windows, and create the following soft link on Linux `ln -s /usr/local/taos/driver/libtaos.so.x.x .x.x /usr/lib/libtaos.so` will work. ## API Reference [API Reference](https://docs.taosdata.com/api/connector-csharp/html/860d2ac1-dd52-39c9-e460-0829c4e5a40b.htm)