C# Connector

    TDengine.Connector 连接器支持通过 TDengine 客户端驱动（taosc）建立与 TDengine 运行实例的连接，提供数据写入、查询、数据订阅、schemaless 数据写入、参数绑定接口数据写入等功能。 TDengine.Connector 自 v3.0.1 起还支持 WebSocket，通过 DSN 建立 WebSocket 连接，提供数据写入、查询、参数绑定接口数据写入等功能。

    本文介绍如何在 Linux 或 Windows 环境中安装 TDengine.Connector，并通过 TDengine.Connector 连接 TDengine 集群，进行数据写入、查询等基本操作。

    注意：TDengine.Connector 3.x 不兼容 TDengine 2.x，如果在运行 TDengine 2.x 版本的环境下需要使用 C# 连接器请使用 TDengine.Connector 的 1.x 版本 。

    TDengine.Connector 的源码托管在 GitHub。

    支持的平台和 TDengine 客户端驱动支持的平台一致。

    版本支持

    请参考

    支持的功能特性

    • 原生连接
    • WebSocket 连接
    1. 连接管理
    2. 普通查询
    3. 连续查询
    4. 参数绑定
    5. 数据订阅（TMQ）

    6. Schemaless

    7. 连接管理

    8. 普通查询
    9. 连续查询
    10. 参数绑定
    • 安装
    • Nuget 客户端 （可选安装）
    • 安装 TDengine 客户端驱动，具体步骤请参考

    安装 TDengine.Connector

    • 使用本地连接
    • 使用 WebSocket 连接

    可以在当前 .NET 项目的路径下，通过 dotnet CLI 添加 Nuget package TDengine.Connector 到当前项目。

    也可以修改当前项目的 .csproj 文件，添加如下 ItemGroup。

    1.   <ItemGroup>
    2.     <PackageReference Include="TDengine.Connector" Version="3.0.*" />
    3.   </ItemGroup>

    需要修改目标项目的 .csproj 项目文件，将 .nupkg 中的 runtimes 目录中的动态库复制到当前项目的 $(OutDir) 目录下。

    1.   <ItemGroup>
    2.     <PackageReference Include="TDengine.Connector" Version="3.0.*" GeneratePathProperty="true" />
    3.   </ItemGroup>
    4.   <Target Name="copyDLLDependency" BeforeTargets="BeforeBuild">
    5.     <ItemGroup>
    6.       <DepDLLFiles Include="$(PkgTDengine_Connector)\runtimes\**\*.*" />
    7.     </ItemGroup>
    8.     <Copy SourceFiles="@(DepDLLFiles)" DestinationFolder="$(OutDir)" />
    9.   </Target>

    建立连接

    • 原生连接
    • WebSocket 连接

    使用 host、username、password、port 等信息建立连接。

    1. using TDengineDriver;
    3. namespace TDengineExample
    4. {
    6.     internal class EstablishConnection
    7.     {
    8.         static void Main(String[] args)
    9.         {
    10.             string host = "localhost";
    11.             short port = 6030;
    12.             string username = "root";
    13.             string password = "taosdata";
    14.             string dbname = "";
    16.             var conn = TDengine.Connect(host, username, password, dbname, port);
    17.             if (conn == IntPtr.Zero)
    18.             {
    19.                 Console.WriteLine("Connect to TDengine failed");
    20.             }
    21.             else
    22.             {
    23.                 Console.WriteLine("Connect to TDengine success");
    24.             }
    25.             TDengine.Close(conn);
    26.             TDengine.Cleanup();
    27.         }
    28.     }
    29. }

    使用 DSN 建立 WebSocket 连接 DSN 连接。 描述字符串基本结构如下：

    1. [<protocol>]://[[<username>:<password>@]<host>:<port>][/<database>][?<p1>=<v1>[&<p2>=<v2>]]
    2. |------------|---|-----------|-----------|------|------|------------|-----------------------|
    3. |   protocol |   | username  | password  | host | port |  database  |  params               |

    各部分意义见下表：

    • protocol: 显示指定以何种方式建立连接，例如：ws://localhost:6041 指定以 Websocket 方式建立连接（支持 http/ws ）。

    • username/password: 用于创建连接的用户名及密码（默认 root/taosdata ）。

    • host/port: 指定创建连接的服务器及端口，WebSocket 连接默认为 localhost:6041 。

    • database: 指定默认连接的数据库名，可选参数。

    • params：其他可选参数。

    查看源码

    使用示例

    SQL 写入

    • 原生连接
    • WebSocket 连接
    1. using TDengineDriver;
    4. namespace TDengineExample
    5. {
    6.     internal class SQLInsertExample
    7.     {
    9.         static void Main()
    10.         {
    11.             IntPtr conn = GetConnection();
    12.             try
    13.             {
    14.                 IntPtr res = TDengine.Query(conn, "CREATE DATABASE power");
    15.                 CheckRes(conn, res, "failed to create database");
    16.                 res = TDengine.Query(conn, "USE power");
    17.                 CheckRes(conn, res, "failed to change database");
    18.                 res = TDengine.Query(conn, "CREATE STABLE power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)");
    19.                 CheckRes(conn, res, "failed to create stable");
    20.                 var sql = "INSERT INTO d1001 USING meters TAGS('California.SanFrancisco', 2) VALUES ('2018-10-03 14:38:05.000', 10.30000, 219, 0.31000) ('2018-10-03 14:38:15.000', 12.60000, 218, 0.33000) ('2018-10-03 14:38:16.800', 12.30000, 221, 0.31000) " +
    21.                             "d1002 USING power.meters TAGS('California.SanFrancisco', 3) VALUES('2018-10-03 14:38:16.650', 10.30000, 218, 0.25000) " +
    22.                             "d1003 USING power.meters TAGS('California.LosAngeles', 2) VALUES('2018-10-03 14:38:05.500', 11.80000, 221, 0.28000)('2018-10-03 14:38:16.600', 13.40000, 223, 0.29000) " +
    23.                             "d1004 USING power.meters TAGS('California.LosAngeles', 3) VALUES('2018-10-03 14:38:05.000', 10.80000, 223, 0.29000)('2018-10-03 14:38:06.500', 11.50000, 221, 0.35000)";
    24.                 res = TDengine.Query(conn, sql);
    25.                 CheckRes(conn, res, "failed to insert data");
    26.                 int affectedRows = TDengine.AffectRows(res);
    27.                 Console.WriteLine("affectedRows " + affectedRows);
    28.                 TDengine.FreeResult(res);
    29.             }
    30.             finally
    31.             {
    32.                 TDengine.Close(conn);
    33.             }
    35.         }
    37.         static IntPtr GetConnection()
    38.         {
    39.             string host = "localhost";
    40.             short port = 6030;
    41.             string username = "root";
    42.             string password = "taosdata";
    43.             string dbname = "";
    44.             var conn = TDengine.Connect(host, username, password, dbname, port);
    45.             if (conn == IntPtr.Zero)
    46.             {
    47.                 throw new Exception("Connect to TDengine failed");
    48.             }
    49.             else
    50.             {
    51.                 Console.WriteLine("Connect to TDengine success");
    52.             }
    53.             return conn;
    54.         }
    56.         static void CheckRes(IntPtr conn, IntPtr res, String errorMsg)
    57.         {
    58.             if (TDengine.ErrorNo(res) != 0)
    59.             {
    60.                 throw new Exception($"{errorMsg} since: {TDengine.Error(res)}");
    61.             }
    62.         }
    64.     }
    65. }
    67. // output:
    68. // Connect to TDengine success
    69. // affectedRows 8

    查看源码

    1. using System;
    2. using TDengineWS.Impl;
    4. namespace Examples
    5. {
    6.     public class WSInsertExample
    7.     {
    8.         static int Main(string[] args)
    9.         {
    10.             string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
    11.             IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
    13.             // Assert if connection is validate
    14.             if (wsConn == IntPtr.Zero)
    15.             {
    16.                 Console.WriteLine("get WS connection failed");
    17.                 return -1;
    18.             }
    19.             else
    20.             {
    21.                 Console.WriteLine("Establish connect success.");
    22.             }
    24.             string createTable = "CREATE STABLE test.meters (ts timestamp, current float, voltage int, phase float) TAGS (location binary(64), groupId int);";
    25.             string insert = "INSERT INTO test.d1001 USING test.meters TAGS('California.SanFrancisco', 2) VALUES ('2018-10-03 14:38:05.000', 10.30000, 219, 0.31000) ('2018-10-03 14:38:15.000', 12.60000, 218, 0.33000) ('2018-10-03 14:38:16.800', 12.30000, 221, 0.31000)" +
    26.                             "test.d1002 USING test.meters TAGS('California.SanFrancisco', 3) VALUES('2018-10-03 14:38:16.650', 10.30000, 218, 0.25000)" +
    27.                             "test.d1003 USING test.meters TAGS('California.LosAngeles', 2) VALUES('2018-10-03 14:38:05.500', 11.80000, 221, 0.28000)('2018-10-03 14:38:16.600', 13.40000, 223, 0.29000) " +
    28.                             "test.d1004 USING test.meters TAGS('California.LosAngeles', 3) VALUES('2018-10-03 14:38:05.000', 10.80000, 223, 0.29000)('2018-10-03 14:38:06.500', 11.50000, 221, 0.35000)";
    30.             IntPtr wsRes = LibTaosWS.WSQuery(wsConn, createTable);
    31.             ValidInsert("create table", wsRes);
    32.             LibTaosWS.WSFreeResult(wsRes);
    34.             wsRes = LibTaosWS.WSQuery(wsConn, insert);
    35.             ValidInsert("insert data", wsRes);
    36.             LibTaosWS.WSFreeResult(wsRes);
    38.             // close connection.
    39.             LibTaosWS.WSClose(wsConn);
    41.             return 0;
    42.         }
    44.         static void ValidInsert(string desc, IntPtr wsRes)
    45.         {
    46.             int code = LibTaosWS.WSErrorNo(wsRes);
    47.             if (code != 0)
    48.             {
    49.                 Console.WriteLine($"execute SQL failed: reason: {LibTaosWS.WSErrorStr(wsRes)}, code:{code}");
    50.             }
    51.             else
    52.             {
    53.                 Console.WriteLine("{0} success affect {2} rows, cost {1} nanoseconds", desc, LibTaosWS.WSTakeTiming(wsRes), LibTaosWS.WSAffectRows(wsRes));
    54.             }
    55.         }
    56.     }
    58. }
    59. // Establish connect success.
    60. // create table success affect 0 rows, cost 3717542 nanoseconds
    61. // insert data success affect 8 rows, cost 2613637 nanoseconds

    InfluxDB 行协议写入

    1. using TDengineDriver;
    3. namespace TDengineExample
    4. {
    5.     internal class InfluxDBLineExample
    6.     {
    7.         static void Main()
    8.         {
    9.             IntPtr conn = GetConnection();
    10.             PrepareDatabase(conn);
    11.             string[] lines = {
    12.                 "meters,location=California.LosAngeles,groupid=2 current=11.8,voltage=221,phase=0.28 1648432611249",
    13.                 "meters,location=California.LosAngeles,groupid=2 current=13.4,voltage=223,phase=0.29 1648432611250",
    14.                 "meters,location=California.LosAngeles,groupid=3 current=10.8,voltage=223,phase=0.29 1648432611249",
    15.                 "meters,location=California.LosAngeles,groupid=3 current=11.3,voltage=221,phase=0.35 1648432611250"
    16.             };
    17.             IntPtr res = TDengine.SchemalessInsert(conn, lines, lines.Length, (int)TDengineSchemalessProtocol.TSDB_SML_LINE_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_MILLI_SECONDS);
    18.             if (TDengine.ErrorNo(res) != 0)
    19.             {
    20.                 throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
    21.             }
    22.             {
    23.                 int affectedRows = TDengine.AffectRows(res);
    24.                 Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
    25.             }
    26.             TDengine.FreeResult(res);
    28.         }
    29.         static IntPtr GetConnection()
    30.         {
    31.             string host = "localhost";
    32.             short port = 6030;
    33.             string username = "root";
    34.             string password = "taosdata";
    35.             string dbname = "";
    36.             var conn = TDengine.Connect(host, username, password, dbname, port);
    37.             if (conn == IntPtr.Zero)
    38.             {
    39.                 throw new Exception("Connect to TDengine failed");
    40.             }
    41.             else
    43.                 Console.WriteLine("Connect to TDengine success");
    44.             }
    45.             return conn;
    46.         }
    48.         static void PrepareDatabase(IntPtr conn)
    49.         {
    50.             IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
    51.             if (TDengine.ErrorNo(res) != 0)
    52.             {
    53.                 throw new Exception("failed to create database, reason: " + TDengine.Error(res));
    54.             }
    55.             res = TDengine.Query(conn, "USE test");
    56.             if (TDengine.ErrorNo(res) != 0)
    57.             {
    58.                 throw new Exception("failed to change database, reason: " + TDengine.Error(res));
    59.             }
    60.         }
    62.     }
    64. }

    OpenTSDB Telnet 行协议写入

    1. using TDengineDriver;
    3. namespace TDengineExample
    4. {
    5.     internal class OptsTelnetExample
    6.     {
    7.         static void Main()
    8.         {
    9.             IntPtr conn = GetConnection();
    10.             try
    11.             {
    12.                 PrepareDatabase(conn);
    13.                 string[] lines = {
    14.                 "meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
    15.                 "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
    16.                 "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
    17.                 "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
    18.                 "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
    19.                 "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
    20.                 "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
    21.                 "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
    22.             };
    23.                 IntPtr res = TDengine.SchemalessInsert(conn, lines, lines.Length, (int)TDengineSchemalessProtocol.TSDB_SML_TELNET_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_NOT_CONFIGURED);
    24.                 if (TDengine.ErrorNo(res) != 0)
    25.                 {
    26.                     throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
    27.                 }
    28.                 else
    29.                 {
    30.                     int affectedRows = TDengine.AffectRows(res);
    31.                     Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
    32.                 }
    33.                 TDengine.FreeResult(res);
    34.             }
    35.             catch
    36.             {
    37.                 TDengine.Close(conn);
    38.             }
    39.         }
    40.         static IntPtr GetConnection()
    41.         {
    42.             string host = "localhost";
    43.             short port = 6030;
    44.             string username = "root";
    45.             string password = "taosdata";
    46.             string dbname = "";
    47.             var conn = TDengine.Connect(host, username, password, dbname, port);
    48.             if (conn == IntPtr.Zero)
    49.             {
    50.                 throw new Exception("Connect to TDengine failed");
    51.             }
    52.             else
    53.             {
    54.                 Console.WriteLine("Connect to TDengine success");
    55.             }
    56.             return conn;
    57.         }
    59.         static void PrepareDatabase(IntPtr conn)
    60.         {
    61.             IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
    62.             if (TDengine.ErrorNo(res) != 0)
    63.             {
    64.                 throw new Exception("failed to create database, reason: " + TDengine.Error(res));
    65.             }
    66.             res = TDengine.Query(conn, "USE test");
    67.             if (TDengine.ErrorNo(res) != 0)
    68.             {
    69.                 throw new Exception("failed to change database, reason: " + TDengine.Error(res));
    70.             }
    71.         }
    72.     }
    73. }

    查看源码

    OpenTSDB JSON 行协议写入

    查看源码

    参数绑定

    • 原生连接
    • WebSocket 连接
    1. using TDengineDriver;
    3. namespace TDengineExample
    4. {
    5.     internal class StmtInsertExample
    6.     {
    7.         private static IntPtr conn;
    8.         private static IntPtr stmt;
    9.         static void Main()
    10.         {
    11.             conn = GetConnection();
    12.             try
    13.             {
    14.                 PrepareSTable();
    15.                 // 1. init and prepare
    16.                 stmt = TDengine.StmtInit(conn);
    17.                 if (stmt == IntPtr.Zero)
    18.                 {
    19.                     throw new Exception("failed to init stmt.");
    20.                 }
    21.                 int res = TDengine.StmtPrepare(stmt, "INSERT INTO ? USING meters TAGS(?, ?) VALUES(?, ?, ?, ?)");
    22.                 CheckStmtRes(res, "failed to prepare stmt");
    24.                 // 2. bind table name and tags
    25.                 TAOS_MULTI_BIND[] tags = new TAOS_MULTI_BIND[2] { TaosMultiBind.MultiBindBinary(new string[] { "California.SanFrancisco" }), TaosMultiBind.MultiBindInt(new int?[] { 2 }) };
    26.                 res = TDengine.StmtSetTbnameTags(stmt, "d1001", tags);
    27.                 CheckStmtRes(res, "failed to bind table name and tags");
    29.                 // 3. bind values
    30.                 TAOS_MULTI_BIND[] values = new TAOS_MULTI_BIND[4] {
    31.                 TaosMultiBind.MultiBindTimestamp(new long[2] { 1648432611249, 1648432611749}),
    32.                 TaosMultiBind.MultiBindFloat(new float?[2] { 10.3f, 12.6f}),
    33.                 TaosMultiBind.MultiBindInt(new int?[2] { 219, 218}),
    34.                 TaosMultiBind.MultiBindFloat(new float?[2]{ 0.31f, 0.33f})
    35.             };
    36.                 res = TDengine.StmtBindParamBatch(stmt, values);
    37.                 CheckStmtRes(res, "failed to bind params");
    39.                 // 4. add batch
    40.                 res = TDengine.StmtAddBatch(stmt);
    41.                 CheckStmtRes(res, "failed to add batch");
    43.                 // 5. execute
    44.                 res = TDengine.StmtExecute(stmt);
    45.                 CheckStmtRes(res, "failed to execute");
    47.                 // 6. free 
    48.                 TaosMultiBind.FreeTaosBind(tags);
    49.                 TaosMultiBind.FreeTaosBind(values);
    50.             }
    51.             finally
    52.             {
    53.                 TDengine.Close(conn);
    54.             }
    56.         }
    58.         static IntPtr GetConnection()
    59.         {
    60.             string host = "localhost";
    61.             short port = 6030;
    62.             string username = "root";
    63.             string password = "taosdata";
    64.             string dbname = "";
    65.             var conn = TDengine.Connect(host, username, password, dbname, port);
    66.             if (conn == IntPtr.Zero)
    67.             {
    68.                 throw new Exception("Connect to TDengine failed");
    69.             }
    70.             else
    71.             {
    72.                 Console.WriteLine("Connect to TDengine success");
    73.             }
    74.             return conn;
    75.         }
    77.         static void PrepareSTable()
    78.         {
    79.             IntPtr res = TDengine.Query(conn, "CREATE DATABASE power");
    80.             CheckResPtr(res, "failed to create database");
    81.             res = TDengine.Query(conn, "USE power");
    82.             CheckResPtr(res, "failed to change database");
    83.             res = TDengine.Query(conn, "CREATE STABLE power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)");
    84.             CheckResPtr(res, "failed to create stable");
    85.         }
    87.         static void CheckStmtRes(int res, string errorMsg)
    88.         {
    89.             if (res != 0)
    90.             {
    91.                 Console.WriteLine(errorMsg + ", " + TDengine.StmtErrorStr(stmt));
    92.                 int code = TDengine.StmtClose(stmt);
    93.                 if (code != 0)
    94.                 {
    95.                     throw new Exception($"failed to close stmt, {code} reason: {TDengine.StmtErrorStr(stmt)} ");
    96.                 }
    97.             }
    98.         }
    100.         static void CheckResPtr(IntPtr res, string errorMsg)
    101.         {
    102.             if (TDengine.ErrorNo(res) != 0)
    103.             {
    104.                 throw new Exception(errorMsg + " since:" + TDengine.Error(res));
    105.             }
    106.         }
    108.     }
    109. }

    查看源码

    1. using System;
    2. using TDengineWS.Impl;
    3. using TDengineDriver;
    4. using System.Runtime.InteropServices;
    6. namespace Examples
    7. {
    8.     public class WSStmtExample
    9.     {
    10.         static int Main(string[] args)
    11.         {
    12.             const string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
    13.             const string table = "meters";
    14.             const string database = "test";
    15.             const string childTable = "d1005";
    16.             string insert = $"insert into ? using {database}.{table} tags(?,?) values(?,?,?,?)";
    17.             const int numOfTags = 2;
    19.             // Establish connection
    20.             IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
    21.             if (wsConn == IntPtr.Zero)
    22.             {
    23.                 Console.WriteLine($"get WS connection failed");
    24.                 return -1;
    25.             }
    26.             else
    27.             {
    29.             }
    31.             // init stmt
    32.             IntPtr wsStmt = LibTaosWS.WSStmtInit(wsConn);
    33.             if (wsStmt != IntPtr.Zero)
    34.             {
    35.                 int code = LibTaosWS.WSStmtPrepare(wsStmt, insert);
    36.                 ValidStmtStep(code, wsStmt, "WSStmtPrepare");
    38.                 TAOS_MULTI_BIND[] wsTags = new TAOS_MULTI_BIND[] { WSMultiBind.WSBindNchar(new string[] { "California.SanDiego" }), WSMultiBind.WSBindInt(new int?[] { 4 }) };
    39.                 code = LibTaosWS.WSStmtSetTbnameTags(wsStmt, $"{database}.{childTable}", wsTags, numOfTags);
    40.                 ValidStmtStep(code, wsStmt, "WSStmtSetTbnameTags");
    42.                 TAOS_MULTI_BIND[] data = new TAOS_MULTI_BIND[4];
    43.                 data[0] = WSMultiBind.WSBindTimestamp(new long[] { 1538548687000, 1538548688000, 1538548689000, 1538548690000, 1538548691000 });
    44.                 data[1] = WSMultiBind.WSBindFloat(new float?[] { 10.30F, 10.40F, 10.50F, 10.60F, 10.70F });
    45.                 data[2] = WSMultiBind.WSBindInt(new int?[] { 223, 221, 222, 220, 219 });
    46.                 data[3] = WSMultiBind.WSBindFloat(new float?[] { 0.31F, 0.32F, 0.33F, 0.35F, 0.28F });
    47.                 code = LibTaosWS.WSStmtBindParamBatch(wsStmt, data, numOfColumns);
    48.                 ValidStmtStep(code, wsStmt, "WSStmtBindParamBatch");
    50.                 code = LibTaosWS.WSStmtAddBatch(wsStmt);
    51.                 ValidStmtStep(code, wsStmt, "WSStmtAddBatch");
    53.                 IntPtr stmtAffectRowPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(Int32)));
    54.                 code = LibTaosWS.WSStmtExecute(wsStmt, stmtAffectRowPtr);
    55.                 ValidStmtStep(code, wsStmt, "WSStmtExecute");
    56.                 Console.WriteLine("WS STMT insert {0} rows...", Marshal.ReadInt32(stmtAffectRowPtr));
    57.                 Marshal.FreeHGlobal(stmtAffectRowPtr);
    59.                 LibTaosWS.WSStmtClose(wsStmt);
    61.                 // Free unmanaged memory
    62.                 WSMultiBind.WSFreeTaosBind(wsTags);
    63.                 WSMultiBind.WSFreeTaosBind(data);
    65.                 //check result with SQL "SELECT * FROM test.d1005;"
    66.             }
    67.             else
    68.             {
    69.                 Console.WriteLine("Init STMT failed...");
    70.             }
    72.             // close connection.
    73.             LibTaosWS.WSClose(wsConn);
    75.             return 0;
    76.         }
    78.         static void ValidStmtStep(int code, IntPtr wsStmt, string desc)
    79.         {
    80.             if (code != 0)
    81.             {
    82.                 Console.WriteLine($"{desc} failed,reason: {LibTaosWS.WSErrorStr(wsStmt)}, code: {code}");
    83.             }
    84.             else
    85.             {
    86.                 Console.WriteLine("{0} success...", desc);
    87.             }
    88.         }
    89.     }
    90. }
    92. // WSStmtPrepare success...
    93. // WSStmtSetTbnameTags success...
    94. // WSStmtBindParamBatch success...
    95. // WSStmtAddBatch success...
    96. // WSStmtExecute success...
    97. // WS STMT insert 5 rows...

    查询数据

    同步查询

    • 原生连接
    • WebSocket 连接
    1. using TDengineDriver;
    2. using TDengineDriver.Impl;
    3. using System.Runtime.InteropServices;
    5. namespace TDengineExample
    6. {
    7.     internal class QueryExample
    8.     {
    9.         static void Main()
    10.         {
    11.             IntPtr conn = GetConnection();
    12.             try
    13.             {
    14.                 // run query
    15.                 IntPtr res = TDengine.Query(conn, "SELECT * FROM meters LIMIT 2");
    16.                 if (TDengine.ErrorNo(res) != 0)
    17.                 {
    18.                     throw new Exception("Failed to query since: " + TDengine.Error(res));
    19.                 }
    21.                 // get filed count
    22.                 int fieldCount = TDengine.FieldCount(res);
    23.                 Console.WriteLine("fieldCount=" + fieldCount);
    25.                 // print column names
    26.                 List<TDengineMeta> metas = LibTaos.GetMeta(res);
    27.                 for (int i = 0; i < metas.Count; i++)
    28.                 {
    29.                     Console.Write(metas[i].name + "\t");
    30.                 }
    31.                 Console.WriteLine();
    33.                 // print values
    34.                 List<Object> resData = LibTaos.GetData(res);
    35.                 for (int i = 0; i < resData.Count; i++)
    36.                 {
    37.                     Console.Write($"|{resData[i].ToString()} \t");
    38.                     if (((i + 1) % metas.Count == 0))
    39.                     {
    40.                         Console.WriteLine("");
    41.                     }
    42.                 }
    43.                 Console.WriteLine();
    45.                 // Free result after use
    46.                 TDengine.FreeResult(res);
    47.             }
    48.             finally
    49.             {
    50.                 TDengine.Close(conn);
    51.             }
    53.         }
    54.         static IntPtr GetConnection()
    55.         {
    56.             string host = "localhost";
    57.             short port = 6030;
    58.             string username = "root";
    59.             string password = "taosdata";
    60.             string dbname = "power";
    61.             var conn = TDengine.Connect(host, username, password, dbname, port);
    62.             if (conn == IntPtr.Zero)
    63.             {
    64.                 throw new Exception("Connect to TDengine failed");
    65.             }
    66.             else
    67.             {
    68.                 Console.WriteLine("Connect to TDengine success");
    69.             }
    70.             return conn;
    71.         }
    72.     }
    73. }
    75. // output:
    76. // Connect to TDengine success
    77. // fieldCount=6
    78. // ts      current voltage phase   location        groupid
    79. // 1648432611249   10.3    219     0.31    California.SanFrancisco        2
    80. // 1648432611749   12.6    218     0.33    California.SanFrancisco        2

    查看源码

    1. using System;
    2. using TDengineWS.Impl;
    3. using System.Collections.Generic;
    4. using TDengineDriver;
    6. namespace Examples
    7. {
    8.     public class WSQueryExample
    9.     {
    10.         static int Main(string[] args)
    11.         {
    12.             string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
    13.             IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
    14.             if (wsConn == IntPtr.Zero)
    15.             {
    16.                 Console.WriteLine("get WS connection failed");
    17.                 return -1;
    18.             }
    19.             else
    20.             {
    21.                 Console.WriteLine("Establish connect success.");
    22.             }
    24.             string select = "select * from test.meters";
    26.             // optional:wsRes = LibTaosWS.WSQuery(wsConn, select);
    27.             IntPtr wsRes = LibTaosWS.WSQueryTimeout(wsConn, select, 1);
    28.             // Assert if query execute success.
    29.             int code = LibTaosWS.WSErrorNo(wsRes);
    30.             if (code != 0)
    31.             {
    32.                 Console.WriteLine($"execute SQL failed: reason: {LibTaosWS.WSErrorStr(wsRes)}, code:{code}");
    33.                 LibTaosWS.WSFreeResult(wsRes);
    34.                 return -1;
    35.             }
    37.             // get meta data
    38.             List<TDengineMeta> metas = LibTaosWS.WSGetFields(wsRes);
    39.             // get retrieved data
    40.             List<object> dataSet = LibTaosWS.WSGetData(wsRes);
    42.             // do something with result.
    43.             foreach (var meta in metas)
    44.             {
    45.                 Console.Write("{0} {1}({2}) \t|\t", meta.name, meta.TypeName(), meta.size);
    46.             }
    47.             Console.WriteLine("");
    49.             for (int i = 0; i < dataSet.Count;)
    50.             {
    51.                 for (int j = 0; j < metas.Count; j++)
    52.                 {
    53.                     Console.Write("{0}\t|\t", dataSet[i]);
    54.                     i++;
    55.                 }
    56.                 Console.WriteLine("");
    57.             }
    59.             // Free result after use.
    60.             LibTaosWS.WSFreeResult(wsRes);
    62.             // close connection.
    63.             LibTaosWS.WSClose(wsConn);
    65.             return 0;
    66.         }
    67.     }
    68. }
    70. // Establish connect success.
    71. // ts TIMESTAMP(8)         |       current FLOAT(4)        |       voltage INT(4)  |       phase FLOAT(4)  |       location BINARY(64)     |       groupid INT(4)  |
    72. // 1538548685000   |       10.8    |       223     |       0.29    |       California.LosAngeles   |       3       |
    73. // 1538548686500   |       11.5    |       221     |       0.35    |       California.LosAngeles   |       3       |
    74. // 1538548685500   |       11.8    |       221     |       0.28    |       California.LosAngeles   |       2       |
    75. // 1538548696600   |       13.4    |       223     |       0.29    |       California.LosAngeles   |       2       |
    76. // 1538548685000   |       10.3    |       219     |       0.31    |       California.SanFrancisco |       2       |
    77. // 1538548695000   |       12.6    |       218     |       0.33    |       California.SanFrancisco |       2       |
    78. // 1538548696800   |       12.3    |       221     |       0.31    |       California.SanFrancisco |       2       |
    79. // 1538548696650   |       10.3    |       218     |       0.25    |       California.SanFrancisco |       3       |

    异步查询

    TDengine.Connector说明
    3.0.2支持 .NET Framework 4.5 及以上，支持 .NET standard 2.0。Nuget Package 包含 WebSocket 动态库。
    3.0.1支持 WebSocket 和 Cloud，查询，插入，参数绑定。
    3.0.0支持 TDengine 3.0.0.0，不兼容 2.x。新增接口TDengine.Impl.GetData()，解析查询结果。
    1.0.7修复 TDengine.Query()内存泄露。
    1.0.6修复 schemaless 在 1.0.4 和 1.0.5 中失效 bug。
    1.0.5修复 Windows 同步查询中文报错 bug。
    1.0.4新增异步查询，订阅等功能。修复绑定参数 bug。
    1.0.3新增参数绑定、schemaless、 json tag等功能。
    1.0.2新增连接管理、同步查询、错误信息等功能。

    其他说明

    第三方驱动

    IoTSharp.Data.Taos 是一个 TDengine 的 ADO.NET 连接器,其中包含了用于EntityFrameworkCore 的提供程序 IoTSharp.EntityFrameworkCore.Taos 和健康检查组件 IoTSharp.HealthChecks.Taos ，支持 Linux，Windows 平台。该连接器由社区贡献者麦壳饼@@maikebing 提供，具体请参考:

    常见问题

    1. “Unable to establish connection”，”Unable to resolve FQDN”

      一般是因为 FQDN 配置不正确。可以参考如何彻底搞懂 TDengine 的 FQDN解决。

    API 参考