C# Connector
TDengine.Connector
是 TDengine 提供的 C# 语言连接器。C# 开发人员可以通过它开发存取 TDengine 集群数据的 C# 应用软件。
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
支持的平台和 TDengine 客户端驱动支持的平台一致。
版本支持
请参考版本支持列表
支持的功能特性
- 原生连接
- WebSocket 连接
- 连接管理
- 普通查询
- 连续查询
- 参数绑定
- 数据订阅(TMQ)
Schemaless
连接管理
- 普通查询
- 连续查询
- 参数绑定
安装步骤
安装前准备
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。
dotnet add package TDengine.Connector
也可以修改当前项目的 .csproj
文件,添加如下 ItemGroup。
<ItemGroup>
<PackageReference Include="TDengine.Connector" Version="3.0.*" />
</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 $(OutDir)
目录下。
<ItemGroup>
<PackageReference Include="TDengine.Connector" Version="3.0.*" GeneratePathProperty="true" />
</ItemGroup>
<Target Name="copyDLLDependency" BeforeTargets="BeforeBuild">
<ItemGroup>
<DepDLLFiles Include="$(PkgTDengine_Connector)\runtimes\**\*.*" />
</ItemGroup>
<Copy SourceFiles="@(DepDLLFiles)" DestinationFolder="$(OutDir)" />
</Target>
注意:TDengine.Connector
自 version>= 3.0.2 的 nuget package 中才会有动态库( taosws.dll,libtaows.so )。
建立连接
- 原生连接
- WebSocket 连接
使用 host、username、password、port 等信息建立连接。
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();
}
}
}
使用 DSN 建立 WebSocket 连接 DSN 连接。 描述字符串基本结构如下:
[<protocol>]://[[<username>:<password>@]<host>:<port>][/<database>][?<p1>=<v1>[&<p2>=<v2>]]
|------------|---|-----------|-----------|------|------|------------|-----------------------|
| 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。
using System;
using TDengineWS.Impl;
namespace Examples
{
public class WSConnExample
{
static int Main(string[] args)
{
string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
if (wsConn == IntPtr.Zero)
{
Console.WriteLine("get WS connection failed");
return -1;
}
else
{
Console.WriteLine("Establish connect success.");
// close connection.
LibTaosWS.WSClose(wsConn);
}
return 0;
}
}
}
使用示例
写入数据
SQL 写入
- 原生连接
- WebSocket 连接
using TDengineDriver;
namespace TDengineExample
{
internal class SQLInsertExample
{
static void Main()
{
IntPtr conn = GetConnection();
try
{
IntPtr res = TDengine.Query(conn, "CREATE DATABASE power");
CheckRes(conn, res, "failed to create database");
res = TDengine.Query(conn, "USE power");
CheckRes(conn, res, "failed to change database");
res = TDengine.Query(conn, "CREATE STABLE power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)");
CheckRes(conn, res, "failed to create stable");
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) " +
"d1002 USING power.meters TAGS('California.SanFrancisco', 3) VALUES('2018-10-03 14:38:16.650', 10.30000, 218, 0.25000) " +
"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) " +
"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)";
res = TDengine.Query(conn, sql);
CheckRes(conn, res, "failed to insert data");
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine("affectedRows " + affectedRows);
TDengine.FreeResult(res);
}
finally
{
TDengine.Close(conn);
}
}
static IntPtr GetConnection()
{
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)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void CheckRes(IntPtr conn, IntPtr res, String errorMsg)
{
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception($"{errorMsg} since: {TDengine.Error(res)}");
}
}
}
}
// output:
// Connect to TDengine success
// affectedRows 8
using System;
using TDengineWS.Impl;
namespace Examples
{
public class WSInsertExample
{
static int Main(string[] args)
{
string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
// Assert if connection is validate
if (wsConn == IntPtr.Zero)
{
Console.WriteLine("get WS connection failed");
return -1;
}
else
{
Console.WriteLine("Establish connect success.");
}
string createTable = "CREATE STABLE test.meters (ts timestamp, current float, voltage int, phase float) TAGS (location binary(64), groupId int);";
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)" +
"test.d1002 USING test.meters TAGS('California.SanFrancisco', 3) VALUES('2018-10-03 14:38:16.650', 10.30000, 218, 0.25000)" +
"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) " +
"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)";
IntPtr wsRes = LibTaosWS.WSQuery(wsConn, createTable);
ValidInsert("create table", wsRes);
LibTaosWS.WSFreeResult(wsRes);
wsRes = LibTaosWS.WSQuery(wsConn, insert);
ValidInsert("insert data", wsRes);
LibTaosWS.WSFreeResult(wsRes);
// close connection.
LibTaosWS.WSClose(wsConn);
return 0;
}
static void ValidInsert(string desc, IntPtr wsRes)
{
int code = LibTaosWS.WSErrorNo(wsRes);
if (code != 0)
{
Console.WriteLine($"execute SQL failed: reason: {LibTaosWS.WSErrorStr(wsRes)}, code:{code}");
}
else
{
Console.WriteLine("{0} success affect {2} rows, cost {1} nanoseconds", desc, LibTaosWS.WSTakeTiming(wsRes), LibTaosWS.WSAffectRows(wsRes));
}
}
}
}
// Establish connect success.
// create table success affect 0 rows, cost 3717542 nanoseconds
// insert data success affect 8 rows, cost 2613637 nanoseconds
InfluxDB 行协议写入
using TDengineDriver;
namespace TDengineExample
{
internal class InfluxDBLineExample
{
static void Main()
{
IntPtr conn = GetConnection();
PrepareDatabase(conn);
string[] lines = {
"meters,location=California.LosAngeles,groupid=2 current=11.8,voltage=221,phase=0.28 1648432611249",
"meters,location=California.LosAngeles,groupid=2 current=13.4,voltage=223,phase=0.29 1648432611250",
"meters,location=California.LosAngeles,groupid=3 current=10.8,voltage=223,phase=0.29 1648432611249",
"meters,location=California.LosAngeles,groupid=3 current=11.3,voltage=221,phase=0.35 1648432611250"
};
IntPtr res = TDengine.SchemalessInsert(conn, lines, lines.Length, (int)TDengineSchemalessProtocol.TSDB_SML_LINE_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_MILLI_SECONDS);
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
}
static IntPtr GetConnection()
{
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)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void PrepareDatabase(IntPtr conn)
{
IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to create database, reason: " + TDengine.Error(res));
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to change database, reason: " + TDengine.Error(res));
}
}
}
}
OpenTSDB Telnet 行协议写入
using TDengineDriver;
namespace TDengineExample
{
internal class OptsTelnetExample
{
static void Main()
{
IntPtr conn = GetConnection();
try
{
PrepareDatabase(conn);
string[] lines = {
"meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
"meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
"meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
"meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
"meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
"meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
"meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
"meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
};
IntPtr res = TDengine.SchemalessInsert(conn, lines, lines.Length, (int)TDengineSchemalessProtocol.TSDB_SML_TELNET_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_NOT_CONFIGURED);
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
}
catch
{
TDengine.Close(conn);
}
}
static IntPtr GetConnection()
{
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)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void PrepareDatabase(IntPtr conn)
{
IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to create database, reason: " + TDengine.Error(res));
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to change database, reason: " + TDengine.Error(res));
}
}
}
}
OpenTSDB JSON 行协议写入
using TDengineDriver;
namespace TDengineExample
{
internal class OptsJsonExample
{
static void Main()
{
IntPtr conn = GetConnection();
try
{
PrepareDatabase(conn);
string[] lines = { "[{\"metric\": \"meters.current\", \"timestamp\": 1648432611249, \"value\": 10.3, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
" {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611249, \"value\": 219, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}, " +
"{\"metric\": \"meters.current\", \"timestamp\": 1648432611250, \"value\": 12.6, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
" {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611250, \"value\": 221, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}]"
};
IntPtr res = TDengine.SchemalessInsert(conn, lines, 1, (int)TDengineSchemalessProtocol.TSDB_SML_JSON_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_NOT_CONFIGURED);
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
}
finally
{
TDengine.Close(conn);
}
}
static IntPtr GetConnection()
{
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)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void PrepareDatabase(IntPtr conn)
{
IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to create database, reason: " + TDengine.Error(res));
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("failed to change database, reason: " + TDengine.Error(res));
}
}
}
}
参数绑定
- 原生连接
- WebSocket 连接
using TDengineDriver;
namespace TDengineExample
{
internal class StmtInsertExample
{
private static IntPtr conn;
private static IntPtr stmt;
static void Main()
{
conn = GetConnection();
try
{
PrepareSTable();
// 1. init and prepare
stmt = TDengine.StmtInit(conn);
if (stmt == IntPtr.Zero)
{
throw new Exception("failed to init stmt.");
}
int res = TDengine.StmtPrepare(stmt, "INSERT INTO ? USING meters TAGS(?, ?) VALUES(?, ?, ?, ?)");
CheckStmtRes(res, "failed to prepare stmt");
// 2. bind table name and tags
TAOS_MULTI_BIND[] tags = new TAOS_MULTI_BIND[2] { TaosMultiBind.MultiBindBinary(new string[] { "California.SanFrancisco" }), TaosMultiBind.MultiBindInt(new int?[] { 2 }) };
res = TDengine.StmtSetTbnameTags(stmt, "d1001", tags);
CheckStmtRes(res, "failed to bind table name and tags");
// 3. bind values
TAOS_MULTI_BIND[] values = new TAOS_MULTI_BIND[4] {
TaosMultiBind.MultiBindTimestamp(new long[2] { 1648432611249, 1648432611749}),
TaosMultiBind.MultiBindFloat(new float?[2] { 10.3f, 12.6f}),
TaosMultiBind.MultiBindInt(new int?[2] { 219, 218}),
TaosMultiBind.MultiBindFloat(new float?[2]{ 0.31f, 0.33f})
};
res = TDengine.StmtBindParamBatch(stmt, values);
CheckStmtRes(res, "failed to bind params");
// 4. add batch
res = TDengine.StmtAddBatch(stmt);
CheckStmtRes(res, "failed to add batch");
// 5. execute
res = TDengine.StmtExecute(stmt);
CheckStmtRes(res, "failed to execute");
// 6. free
TaosMultiBind.FreeTaosBind(tags);
TaosMultiBind.FreeTaosBind(values);
}
finally
{
TDengine.Close(conn);
}
}
static IntPtr GetConnection()
{
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)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void PrepareSTable()
{
IntPtr res = TDengine.Query(conn, "CREATE DATABASE power");
CheckResPtr(res, "failed to create database");
res = TDengine.Query(conn, "USE power");
CheckResPtr(res, "failed to change database");
res = TDengine.Query(conn, "CREATE STABLE power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)");
CheckResPtr(res, "failed to create stable");
}
static void CheckStmtRes(int res, string errorMsg)
{
if (res != 0)
{
Console.WriteLine(errorMsg + ", " + TDengine.StmtErrorStr(stmt));
int code = TDengine.StmtClose(stmt);
if (code != 0)
{
throw new Exception($"failed to close stmt, {code} reason: {TDengine.StmtErrorStr(stmt)} ");
}
}
}
static void CheckResPtr(IntPtr res, string errorMsg)
{
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception(errorMsg + " since:" + TDengine.Error(res));
}
}
}
}
using System;
using TDengineWS.Impl;
using TDengineDriver;
using System.Runtime.InteropServices;
namespace Examples
{
public class WSStmtExample
{
static int Main(string[] args)
{
const string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
const string table = "meters";
const string database = "test";
const string childTable = "d1005";
string insert = $"insert into ? using {database}.{table} tags(?,?) values(?,?,?,?)";
const int numOfTags = 2;
const int numOfColumns = 4;
// Establish connection
IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
if (wsConn == IntPtr.Zero)
{
Console.WriteLine($"get WS connection failed");
return -1;
}
else
{
Console.WriteLine("Establish connect success...");
}
// init stmt
IntPtr wsStmt = LibTaosWS.WSStmtInit(wsConn);
if (wsStmt != IntPtr.Zero)
{
int code = LibTaosWS.WSStmtPrepare(wsStmt, insert);
ValidStmtStep(code, wsStmt, "WSStmtPrepare");
TAOS_MULTI_BIND[] wsTags = new TAOS_MULTI_BIND[] { WSMultiBind.WSBindNchar(new string[] { "California.SanDiego" }), WSMultiBind.WSBindInt(new int?[] { 4 }) };
code = LibTaosWS.WSStmtSetTbnameTags(wsStmt, $"{database}.{childTable}", wsTags, numOfTags);
ValidStmtStep(code, wsStmt, "WSStmtSetTbnameTags");
TAOS_MULTI_BIND[] data = new TAOS_MULTI_BIND[4];
data[0] = WSMultiBind.WSBindTimestamp(new long[] { 1538548687000, 1538548688000, 1538548689000, 1538548690000, 1538548691000 });
data[1] = WSMultiBind.WSBindFloat(new float?[] { 10.30F, 10.40F, 10.50F, 10.60F, 10.70F });
data[2] = WSMultiBind.WSBindInt(new int?[] { 223, 221, 222, 220, 219 });
data[3] = WSMultiBind.WSBindFloat(new float?[] { 0.31F, 0.32F, 0.33F, 0.35F, 0.28F });
code = LibTaosWS.WSStmtBindParamBatch(wsStmt, data, numOfColumns);
ValidStmtStep(code, wsStmt, "WSStmtBindParamBatch");
code = LibTaosWS.WSStmtAddBatch(wsStmt);
ValidStmtStep(code, wsStmt, "WSStmtAddBatch");
IntPtr stmtAffectRowPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(Int32)));
code = LibTaosWS.WSStmtExecute(wsStmt, stmtAffectRowPtr);
ValidStmtStep(code, wsStmt, "WSStmtExecute");
Console.WriteLine("WS STMT insert {0} rows...", Marshal.ReadInt32(stmtAffectRowPtr));
Marshal.FreeHGlobal(stmtAffectRowPtr);
LibTaosWS.WSStmtClose(wsStmt);
// Free unmanaged memory
WSMultiBind.WSFreeTaosBind(wsTags);
WSMultiBind.WSFreeTaosBind(data);
//check result with SQL "SELECT * FROM test.d1005;"
}
else
{
Console.WriteLine("Init STMT failed...");
}
// close connection.
LibTaosWS.WSClose(wsConn);
return 0;
}
static void ValidStmtStep(int code, IntPtr wsStmt, string desc)
{
if (code != 0)
{
Console.WriteLine($"{desc} failed,reason: {LibTaosWS.WSErrorStr(wsStmt)}, code: {code}");
}
else
{
Console.WriteLine("{0} success...", desc);
}
}
}
}
// WSStmtPrepare success...
// WSStmtSetTbnameTags success...
// WSStmtBindParamBatch success...
// WSStmtAddBatch success...
// WSStmtExecute success...
// WS STMT insert 5 rows...
查询数据
同步查询
- 原生连接
- WebSocket 连接
using TDengineDriver;
using TDengineDriver.Impl;
using System.Runtime.InteropServices;
namespace TDengineExample
{
internal class QueryExample
{
static void Main()
{
IntPtr conn = GetConnection();
try
{
// run query
IntPtr res = TDengine.Query(conn, "SELECT * FROM meters LIMIT 2");
if (TDengine.ErrorNo(res) != 0)
{
throw new Exception("Failed to query since: " + TDengine.Error(res));
}
// get filed count
int fieldCount = TDengine.FieldCount(res);
Console.WriteLine("fieldCount=" + fieldCount);
// print column names
List<TDengineMeta> metas = LibTaos.GetMeta(res);
for (int i = 0; i < metas.Count; i++)
{
Console.Write(metas[i].name + "\t");
}
Console.WriteLine();
// print values
List<Object> resData = LibTaos.GetData(res);
for (int i = 0; i < resData.Count; i++)
{
Console.Write($"|{resData[i].ToString()} \t");
if (((i + 1) % metas.Count == 0))
{
Console.WriteLine("");
}
}
Console.WriteLine();
// Free result after use
TDengine.FreeResult(res);
}
finally
{
TDengine.Close(conn);
}
}
static IntPtr GetConnection()
{
string host = "localhost";
short port = 6030;
string username = "root";
string password = "taosdata";
string dbname = "power";
var conn = TDengine.Connect(host, username, password, dbname, port);
if (conn == IntPtr.Zero)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
}
}
// output:
// Connect to TDengine success
// fieldCount=6
// ts current voltage phase location groupid
// 1648432611249 10.3 219 0.31 California.SanFrancisco 2
// 1648432611749 12.6 218 0.33 California.SanFrancisco 2
using System;
using TDengineWS.Impl;
using System.Collections.Generic;
using TDengineDriver;
namespace Examples
{
public class WSQueryExample
{
static int Main(string[] args)
{
string DSN = "ws://root:taosdata@127.0.0.1:6041/test";
IntPtr wsConn = LibTaosWS.WSConnectWithDSN(DSN);
if (wsConn == IntPtr.Zero)
{
Console.WriteLine("get WS connection failed");
return -1;
}
else
{
Console.WriteLine("Establish connect success.");
}
string select = "select * from test.meters";
// optional:wsRes = LibTaosWS.WSQuery(wsConn, select);
IntPtr wsRes = LibTaosWS.WSQueryTimeout(wsConn, select, 1);
// Assert if query execute success.
int code = LibTaosWS.WSErrorNo(wsRes);
if (code != 0)
{
Console.WriteLine($"execute SQL failed: reason: {LibTaosWS.WSErrorStr(wsRes)}, code:{code}");
LibTaosWS.WSFreeResult(wsRes);
return -1;
}
// get meta data
List<TDengineMeta> metas = LibTaosWS.WSGetFields(wsRes);
// get retrieved data
List<object> dataSet = LibTaosWS.WSGetData(wsRes);
// do something with result.
foreach (var meta in metas)
{
Console.Write("{0} {1}({2}) \t|\t", meta.name, meta.TypeName(), meta.size);
}
Console.WriteLine("");
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("");
}
// Free result after use.
LibTaosWS.WSFreeResult(wsRes);
// close connection.
LibTaosWS.WSClose(wsConn);
return 0;
}
}
}
// Establish connect success.
// ts TIMESTAMP(8) | current FLOAT(4) | voltage INT(4) | phase FLOAT(4) | location BINARY(64) | groupid INT(4) |
// 1538548685000 | 10.8 | 223 | 0.29 | California.LosAngeles | 3 |
// 1538548686500 | 11.5 | 221 | 0.35 | California.LosAngeles | 3 |
// 1538548685500 | 11.8 | 221 | 0.28 | California.LosAngeles | 2 |
// 1538548696600 | 13.4 | 223 | 0.29 | California.LosAngeles | 2 |
// 1538548685000 | 10.3 | 219 | 0.31 | California.SanFrancisco | 2 |
// 1538548695000 | 12.6 | 218 | 0.33 | California.SanFrancisco | 2 |
// 1538548696800 | 12.3 | 221 | 0.31 | California.SanFrancisco | 2 |
// 1538548696650 | 10.3 | 218 | 0.25 | California.SanFrancisco | 3 |
异步查询
using System;
using System.Collections.Generic;
using TDengineDriver;
using TDengineDriver.Impl;
using System.Runtime.InteropServices;
namespace TDengineExample
{
public class AsyncQueryExample
{
static void Main()
{
IntPtr conn = GetConnection();
try
{
QueryAsyncCallback queryAsyncCallback = new QueryAsyncCallback(QueryCallback);
TDengine.QueryAsync(conn, "select * from meters", queryAsyncCallback, IntPtr.Zero);
Thread.Sleep(2000);
}
finally
{
TDengine.Close(conn);
}
}
static void QueryCallback(IntPtr param, IntPtr taosRes, int code)
{
if (code == 0 && taosRes != IntPtr.Zero)
{
FetchRawBlockAsyncCallback fetchRowAsyncCallback = new FetchRawBlockAsyncCallback(FetchRawBlockCallback);
TDengine.FetchRawBlockAsync(taosRes, fetchRowAsyncCallback, param);
}
else
{
throw new Exception($"async query data failed,code:{code},reason:{TDengine.Error(taosRes)}");
}
}
// Iteratively call this interface until "numOfRows" is no greater than 0.
static void FetchRawBlockCallback(IntPtr param, IntPtr taosRes, int numOfRows)
{
if (numOfRows > 0)
{
Console.WriteLine($"{numOfRows} rows async retrieved");
IntPtr pdata = TDengine.GetRawBlock(taosRes);
List<TDengineMeta> metaList = TDengine.FetchFields(taosRes);
List<object> dataList = LibTaos.ReadRawBlock(pdata, metaList, numOfRows);
for (int i = 0; i < dataList.Count; i++)
{
if (i != 0 && (i + 1) % metaList.Count == 0)
{
Console.WriteLine("{0}\t|", dataList[i]);
}
else
{
Console.Write("{0}\t|", dataList[i]);
}
}
Console.WriteLine("");
TDengine.FetchRawBlockAsync(taosRes, FetchRawBlockCallback, param);
}
else
{
if (numOfRows == 0)
{
Console.WriteLine("async retrieve complete.");
}
else
{
throw new Exception($"FetchRawBlockCallback callback error, error code {numOfRows}");
}
TDengine.FreeResult(taosRes);
}
}
static IntPtr GetConnection()
{
string host = "localhost";
short port = 6030;
string username = "root";
string password = "taosdata";
string dbname = "power";
var conn = TDengine.Connect(host, username, password, dbname, port);
if (conn == IntPtr.Zero)
{
throw new Exception("Connect to TDengine failed");
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
}
}
// //output:
// // Connect to TDengine success
// // 8 rows async retrieved
// // 1538548685500 | 11.8 | 221 | 0.28 | california.losangeles | 2 |
// // 1538548696600 | 13.4 | 223 | 0.29 | california.losangeles | 2 |
// // 1538548685000 | 10.8 | 223 | 0.29 | california.losangeles | 3 |
// // 1538548686500 | 11.5 | 221 | 0.35 | california.losangeles | 3 |
// // 1538548685000 | 10.3 | 219 | 0.31 | california.sanfrancisco | 2 |
// // 1538548695000 | 12.6 | 218 | 0.33 | california.sanfrancisco | 2 |
// // 1538548696800 | 12.3 | 221 | 0.31 | california.sanfrancisco | 2 |
// // 1538548696650 | 10.3 | 218 | 0.25 | california.sanfrancisco | 3 |
// // async retrieve complete.
更多示例程序
示例程序 | 示例程序描述 |
---|---|
CURD | 使用 TDengine.Connector 实现的建表、插入、查询示例 |
JSON Tag | 使用 TDengine.Connector 实现的写入和查询 JSON tag 类型数据的示例 |
stmt | 使用 TDengine.Connector 实现的参数绑定插入和查询的示例 |
schemaless | 使用 TDengine.Connector 实现的使用 schemaless 写入的示例 |
async query | 使用 TDengine.Connector 实现的异步查询的示例 |
数据订阅(TMQ) | 使用 TDengine.Connector 实现的订阅数据的示例 |
Basic WebSocket Usage | 使用 TDengine.Connector 的 WebSocket 基本的示例 |
Basic WebSocket STMT | 使用 TDengine.Connector 的 WebSocket STMT 基本的示例 |
重要更新记录
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:
- 接口下载: https://github.com/IoTSharp/EntityFrameworkCore.Taos
- 用法说明:https://www.taosdata.com/blog/2020/11/02/1901.html
常见问题
“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。
Unhandled exception. System.DllNotFoundException: Unable to load DLL ‘taos’ or one of its dependencies: 找不到指定的模块。
一般是因为程序没有找到依赖的客户端驱动。解决方法为:Windows 下可以将
C:\TDengine\driver\taos.dll
拷贝到C:\Windows\System32\
目录下,Linux 下建立如下软链接ln -s /usr/local/taos/driver/libtaos.so.x.x.x.x /usr/lib/libtaos.so
即可。