docs: csharp 3.0 cloud doc and sample (#16630)

* docs(cloud):Add C# could doc and examples

* docs(cloud):update C# Cloud docs

docs/en/15-programming/01-connect/06-csharp.md

+---
+sidebar_label: C#
+title: Connect with C# Connector
+description: Connect to TDengine cloud service using C# connector
+---
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Create Project
+
+```bash
+dotnet new console -o example
+```
+
+## Add C# TDengine Driver class lib
+
+```bash
+cd example
+dotnet add package TDengine.Connector
+```
+
+## Config
+
+Run this command in your terminal to save TDengine cloud token as variables:
+
+<Tabs defaultValue="bash">
+<TabItem value="bash" label="Bash">
+
+```bash
+export TDENGINE_CLOUD_DSN="<DSN>"
+```
+
+</TabItem>
+<TabItem value="cmd" label="CMD">
+
+```bash
+set TDENGINE_CLOUD_DSN="<DSN>"
+```
+
+</TabItem>
+<TabItem value="powershell" label="Powershell">
+
+```powershell
+$env:TDENGINE_CLOUD_DSN="<DSN>"
+```
+
+</TabItem>
+</Tabs>
+
+
+<!-- exclude -->
+:::note
+Replace  <DSN\> with real TDengine cloud DSN. To obtain the real value, please log in [TDengine Cloud](https://cloud.tdengine.com) and click "Connector" and then select "C#".
+
+:::
+<!-- exclude-end -->
+
+## Connect
+
+``` XML
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>
+```
+
+```C#
+{{#include docs/examples/csharp/cloud-example/Connect.cs}}
+```

docs/en/15-programming/06-connector/06-csharp.md

+---
+sidebar_label: C#
+title: TDengine C# Connector
+description: Detailed guide for C# Connector
+---
+
+ `TDengine.Connector` is the official C# connector for TDengine. C# developers can develop applications to access TDengine instance data.
+
+The source code for `TDengine.Connector` is hosted on [GitHub](https://github.com/taosdata/taos-connector-dotnet/tree/3.0).
+
+## Installation
+
+### Pre-installation
+
+Install the .NET deployment SDK.
+
+### Add TDengine.Connector through Nuget
+
+```bash
+dotnet add package TDengine.Connector
+```
+
+## Establishing a connection
+
+``` XML
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>
+```
+
+``` C#
+{{#include docs/examples/csharp/cloud-example/connect/Program.cs}}
+```
+
+## Usage examples
+
+### Basic Insert and Query
+
+``` XML
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>
+
+```
+
+```C#
+{{#include docs/examples/csharp/cloud-example/usage/Program.cs}}
+```
+
+### STMT Insert
+
+``` XML
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>
+
+```
+
+```C#
+{{#include docs/examples/csharp/cloud-example/stmt/Program.cs}}
+```
+
+## Important Updates
+
+| TDengine.Connector | Description |
+| ------------------------- | ---------------------------------------------------------------- |
+| 3.0.1 | Support connect to TDengine cloud service
+
+## API Reference
+
+[API Reference](https://docs.taosdata.com/api/connector-csharp/html/860d2ac1-dd52-39c9-e460-0829c4e5a40b.htm)

docs/examples/csharp/.gitignore

-bin
-obj
-.vs
-*.sln
+cloud-example/connect/bin
+cloud-example/connect/obj
+cloud-example/usage/bin
+cloud-example/usage/obj
\ No newline at end of file
+cloud-example/stmt/bin
+cloud-example/stmt/obj
+.vs
\ No newline at end of file

docs/examples/csharp/cloud-example/cloud-example.sln

+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30114.105
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "connect", "connect\connect.csproj", "{4006CF0C-17BE-4508-9682-A85298F8C92D}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "usage", "usage\usage.csproj", "{243C420F-FC47-4F21-B81E-83CDE91F2D47}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "stmt", "stmt\stmt.csproj", "{B6907CB6-41CB-4644-AEE1-551456EADE12}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{4006CF0C-17BE-4508-9682-A85298F8C92D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4006CF0C-17BE-4508-9682-A85298F8C92D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4006CF0C-17BE-4508-9682-A85298F8C92D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4006CF0C-17BE-4508-9682-A85298F8C92D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{243C420F-FC47-4F21-B81E-83CDE91F2D47}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{243C420F-FC47-4F21-B81E-83CDE91F2D47}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{243C420F-FC47-4F21-B81E-83CDE91F2D47}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{243C420F-FC47-4F21-B81E-83CDE91F2D47}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B6907CB6-41CB-4644-AEE1-551456EADE12}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B6907CB6-41CB-4644-AEE1-551456EADE12}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B6907CB6-41CB-4644-AEE1-551456EADE12}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B6907CB6-41CB-4644-AEE1-551456EADE12}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

docs/examples/csharp/cloud-example/connect/Program.cs

+using System;
+using TDengineWS.Impl;
+
+namespace Cloud.Examples
+{
+    public class ConnectExample
+    {
+        static void Main(string[] args)
+        {
+            string dsn = Environment.GetEnvironmentVariable("TDENGINE_CLOUD_DSN");
+            Connect(dsn);
+        }
+
+        public static void Connect(string dsn)
+        {
+            // get connect
+            IntPtr conn = LibTaosWS.WSConnectWithDSN(dsn);
+            if (conn == IntPtr.Zero)
+            {
+                throw new Exception($"get connection failed,reason:{LibTaosWS.WSErrorStr(conn)},code:{LibTaosWS.WSErrorNo(conn)}");
+            }
+            else
+            {
+                Console.WriteLine("Establish connect success.");
+            }
+
+            // do something ...
+
+            // close connect
+            LibTaosWS.WSClose(conn);
+
+        }
+    }
+}
\ No newline at end of file

docs/examples/csharp/cloud-example/connect/connect.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>

docs/examples/csharp/cloud-example/stmt/Program.cs

+using System;
+using TDengineWS.Impl;
+using TDengineDriver;
+using System.Runtime.InteropServices;
+
+namespace Cloud.Examples
+{
+    public class STMTExample
+    {
+        static void Main(string[] args)
+        {
+            string dsn = Environment.GetEnvironmentVariable("TDENGINE_CLOUD_DSN");
+            IntPtr conn = Connect(dsn);
+            // assume table has been created.
+            // CREATE STABLE if not exists test.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)
+            string insert = "insert into ? using test.meters tags(?,?) values(?,?,?,?)";
+
+            // Init STMT
+            IntPtr stmt = LibTaosWS.WSStmtInit(conn);
+
+            if (stmt != IntPtr.Zero)
+            {
+                // Prepare SQL
+                int code = LibTaosWS.WSStmtPrepare(stmt, insert);
+                ValidSTMTStep(code, stmt, "WSInit()");
+
+                // Bind child table name and tags
+                TAOS_MULTI_BIND[] tags = new TAOS_MULTI_BIND[2] { WSMultiBind.WSBindBinary(new string[] { "California.LosAngeles" }), WSMultiBind.WSBindInt(new int?[] { 6 }) };
+                code = LibTaosWS.WSStmtSetTbnameTags(stmt, "test.d1005",tags, 2);
+                ValidSTMTStep(code, stmt, "WSStmtSetTbnameTags()");
+
+                // bind column value
+                TAOS_MULTI_BIND[] data = new TAOS_MULTI_BIND[4];
+                data[0] = WSMultiBind.WSBindTimestamp(new long[] { 1538551000000, 1538552000000, 1538553000000, 1538554000000, 1538555000000 });
+                data[1] = WSMultiBind.WSBindFloat(new float?[] { 10.30000F, 10.30000F, 11.30000F, 10.30000F, 10.80000F });
+                data[2] = WSMultiBind.WSBindInt(new int?[] { 218, 219, 221, 222, 223 });
+                data[3] = WSMultiBind.WSBindFloat(new float?[] { 0.28000F, 0.29000F, 0.30000F, 0.31000F, 0.32000F });
+                code = LibTaosWS.WSStmtBindParamBatch(stmt, data, 4);
+                ValidSTMTStep(code, stmt, "WSStmtBindParamBatch");
+
+                LibTaosWS.WSStmtAddBatch(stmt);
+                ValidSTMTStep(code, stmt, "WSStmtAddBatch");
+
+                IntPtr affectRowPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(Int32)));
+                LibTaosWS.WSStmtExecute(stmt, affectRowPtr);
+                ValidSTMTStep(code, stmt, "WSStmtExecute");
+                Console.WriteLine("STMT affect rows:{0}", Marshal.ReadInt32(affectRowPtr));
+
+                LibTaosWS.WSStmtClose(stmt);
+
+                // Free allocated memory
+                Marshal.FreeHGlobal(affectRowPtr);
+                WSMultiBind.WSFreeTaosBind(tags);
+                WSMultiBind.WSFreeTaosBind(data);
+            }
+            // close connect
+            LibTaosWS.WSClose(conn);
+        }
+
+        public static IntPtr Connect(string dsn)
+        {
+            // get connect
+            IntPtr conn = LibTaosWS.WSConnectWithDSN(dsn);
+            if (conn == IntPtr.Zero)
+            {
+                throw new Exception($"get connection failed,reason:{LibTaosWS.WSErrorStr(conn)},code:{LibTaosWS.WSErrorNo(conn)}");
+            }
+            return conn;
+        }
+
+        public static void ValidSTMTStep(int code, IntPtr wsStmt, string method)
+        {
+            if (code != 0)
+            {
+                throw new Exception($"{method} failed,reason: {LibTaosWS.WSErrorStr(wsStmt)}, code: {code}");
+            }
+            else
+            {
+                Console.WriteLine("{0} success", method);
+            }
+        }
+    }
+}
\ No newline at end of file

docs/examples/csharp/cloud-example/stmt/stmt.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>

docs/examples/csharp/cloud-example/usage/Program.cs

+using System;
+using TDengineDriver;
+using TDengineWS.Impl;
+using System.Collections.Generic;
+
+namespace Cloud.Examples
+{
+    public class UsageExample
+    {
+        static void Main(string[] args)
+        {
+            string dsn = Environment.GetEnvironmentVariable("TDENGINE_CLOUD_DSN");
+            IntPtr conn = Connect(dsn);
+            InsertData(conn);
+            SelectData(conn);
+            // close connect
+            LibTaosWS.WSClose(conn);
+        }
+
+        public static IntPtr Connect(string dsn)
+        {
+            // get connect
+            IntPtr conn = LibTaosWS.WSConnectWithDSN(dsn);
+            if (conn == IntPtr.Zero)
+            {
+                throw new Exception($"get connection failed,reason:{LibTaosWS.WSErrorStr(conn)},code:{LibTaosWS.WSErrorNo(conn)}");
+            }
+            return conn;
+        }
+
+
+        public static void InsertData(IntPtr conn)
+        {
+            string createTable = "CREATE STABLE if not exists test.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)";
+            string insertData = "INSERT INTO " +
+                                "test.d1001 USING test.meters TAGS('California.SanFrancisco', 1) VALUES ('2018-10-03 14:38:05.000', 10.30000, 219, 0.31000)" +
+                                "test.d1002 USING test.meters TAGS('California.SanFrancisco', 2) VALUES ('2018-10-03 14:38:16.650', 10.30000, 218, 0.25000)" +
+                                "test.d1003 USING test.meters TAGS('California.LosAngeles', 3) VALUES ('2018-10-03 14:38:05.500', 11.80000, 221, 0.28000)" +
+                                "test.d1004 USING test.meters TAGS('California.LosAngeles', 4) VALUES ('2018-10-03 14:38:05.000', 10.80000, 223, 0.29000) ";
+
+            // create database under database named 'test'
+            IntPtr res = LibTaosWS.WSQuery(conn, createTable);
+            ValidQueryExecution(res);
+            // Free the query result every time when used up it.
+            LibTaosWS.WSFreeResult(res);
+
+            // insert data into the table created in previous step.
+            res = LibTaosWS.WSQuery(conn, insertData);
+            ValidQueryExecution(res);
+            // Free the query result every time when used up it.
+            LibTaosWS.WSFreeResult(res);
+        }
+        public static void SelectData(IntPtr conn)
+        {
+            string selectTable = "select * from test.meters";
+            IntPtr res = LibTaosWS.WSQueryTimeout(conn, selectTable,5000);
+            ValidQueryExecution(res);
+
+            // print meta
+            List<TDengineMeta> metas = LibTaosWS.WSGetFields(res);
+            foreach (var meta in metas)
+            {
+                Console.Write("{0} {1}({2})\t|", meta.name, meta.TypeName(), meta.size);
+            }
+            Console.WriteLine("");
+            List<object> dataSet = LibTaosWS.WSGetData(res);
+            for (int i = 0; i < dataSet.Count;)
+            {
+                for (int j = 0; j < metas.Count; j++)
+                {
+                    Console.Write("{0}\t|\t", dataSet[i]);
+                    i++;
+                }
+                Console.WriteLine("");
+            }
+            Console.WriteLine("");
+
+            // Free the query result every time when used up it.
+            LibTaosWS.WSFreeResult(res);
+        }
+
+        // Check if LibTaosWS.Query() execute correctly.
+        public static void ValidQueryExecution(IntPtr res)
+        {
+            int code = LibTaosWS.WSErrorNo(res);
+            if (code != 0)
+            {
+                throw new Exception($"execute SQL failed: reason: {LibTaosWS.WSErrorStr(res)}, code:{code}");
+            }
+        }
+    }
+}
\ No newline at end of file

docs/examples/csharp/cloud-example/usage/usage.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="TDengine.Connector" Version="3.0.1" />
+  </ItemGroup>
+
+</Project>