C# Connector
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 REST 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.
Supported Platforms
The supported platforms are the same as those supported by the TDengine client driver.
Version support
Please refer to version support list
Supported features
- Connection Management
- General Query
- Continuous Query
- Parameter Binding
- Subscription
- Schemaless
Installation Steps
Pre-installation preparation
- Install the .NET SDK
- Nuget Client (optional installation)
- Install TDengine client driver, please refer to Install client driver for details
Install via dotnet CLI
- Get C# driver using dotnet CLI
- Use source code to get C# driver
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.
dotnet add package TDengine.Connector
You can download TDengine's source code and directly reference the latest version of the TDengine.Connector library
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
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
using TDengineDriver;
namespace TDengineExample
{
internal class SQLInsertExample
{
static void Main()
{
IntPtr conn = GetConnection();
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);
ExitProgram(conn, 0);
}
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)
{
Console.WriteLine("Connect to TDengine failed");
Environment.Exit(0);
}
else
{
Console.WriteLine("Connect to TDengine success");
}
return conn;
}
static void CheckRes(IntPtr conn, IntPtr res, String errorMsg)
{
if (TDengine.ErrorNo(res) != 0)
{
Console.Write(errorMsg + " since: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
}
static void ExitProgram(IntPtr conn, int exitCode)
{
TDengine.Close(conn);
TDengine.Cleanup();
Environment.Exit(exitCode);
}
}
}
// output:
// Connect to TDengine success
// affectedRows 8
InfluxDB line protocol write
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)
{
Console.WriteLine("SchemalessInsert failed since " + TDengine.Error(res));
ExitProgram(conn, 1);
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
ExitProgram(conn, 0);
}
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)
{
Console.WriteLine("Connect to TDengine failed");
TDengine.Cleanup();
Environment.Exit(1);
}
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)
{
Console.WriteLine("failed to create database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
Console.WriteLine("failed to change database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
}
static void ExitProgram(IntPtr conn, int exitCode)
{
TDengine.Close(conn);
TDengine.Cleanup();
Environment.Exit(exitCode);
}
}
}
OpenTSDB Telnet line protocol write
using TDengineDriver;
namespace TDengineExample
{
internal class OptsTelnetExample
{
static void Main()
{
IntPtr conn = GetConnection();
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)
{
Console.WriteLine("SchemalessInsert failed since " + TDengine.Error(res));
ExitProgram(conn, 1);
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
ExitProgram(conn, 0);
}
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)
{
Console.WriteLine("Connect to TDengine failed");
TDengine.Cleanup();
Environment.Exit(1);
}
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)
{
Console.WriteLine("failed to create database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
Console.WriteLine("failed to change database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
}
static void ExitProgram(IntPtr conn, int exitCode)
{
TDengine.Close(conn);
TDengine.Cleanup();
Environment.Exit(exitCode);
}
}
}
OpenTSDB JSON line protocol write
using TDengineDriver;
namespace TDengineExample
{
internal class OptsJsonExample
{
static void Main()
{
IntPtr conn = GetConnection();
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)
{
Console.WriteLine("SchemalessInsert failed since " + TDengine.Error(res));
ExitProgram(conn, 1);
}
else
{
int affectedRows = TDengine.AffectRows(res);
Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
}
TDengine.FreeResult(res);
ExitProgram(conn, 0);
}
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)
{
Console.WriteLine("Connect to TDengine failed");
TDengine.Cleanup();
Environment.Exit(1);
}
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)
{
Console.WriteLine("failed to create database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
res = TDengine.Query(conn, "USE test");
if (TDengine.ErrorNo(res) != 0)
{
Console.WriteLine("failed to change database, reason: " + TDengine.Error(res));
ExitProgram(conn, 1);
}
}
static void ExitProgram(IntPtr conn, int exitCode)
{
TDengine.Close(conn);
TDengine.Cleanup();
Environment.Exit(exitCode);
}
}
}
Query data
Synchronous Query
using TDengineDriver;
using System.Runtime.InteropServices;
namespace TDengineExample
{
internal class QueryExample
{
static void Main()
{
IntPtr conn = GetConnection();
// run query
IntPtr res = TDengine.Query(conn, "SELECT * FROM test.meters LIMIT 2");
if (TDengine.ErrorNo(res) != 0)
{
Console.WriteLine("Failed to query since: " + TDengine.Error(res));
TDengine.Close(conn);
TDengine.Cleanup();
return;
}
// get filed count
int fieldCount = TDengine.FieldCount(res);
Console.WriteLine("fieldCount=" + fieldCount);
// print column names
List<TDengineMeta> metas = TDengine.FetchFields(res);
for (int i = 0; i < metas.Count; i++)
{
Console.Write(metas[i].name + "\t");
}
Console.WriteLine();
// print values
IntPtr row;
while ((row = TDengine.FetchRows(res)) != IntPtr.Zero)
{
List<TDengineMeta> metaList = TDengine.FetchFields(res);
int numOfFiled = TDengine.FieldCount(res);
List<String> dataRaw = new List<string>();
IntPtr colLengthPrt = TDengine.FetchLengths(res);
int[] colLengthArr = new int[numOfFiled];
Marshal.Copy(colLengthPrt, colLengthArr, 0, numOfFiled);
for (int i = 0; i < numOfFiled; i++)
{
TDengineMeta meta = metaList[i];
IntPtr data = Marshal.ReadIntPtr(row, IntPtr.Size * i);
if (data == IntPtr.Zero)
{
Console.Write("NULL\t");
continue;
}
switch ((TDengineDataType)meta.type)
{
case TDengineDataType.TSDB_DATA_TYPE_BOOL:
bool v1 = Marshal.ReadByte(data) == 0 ? false : true;
Console.Write(v1.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_TINYINT:
sbyte v2 = (sbyte)Marshal.ReadByte(data);
Console.Write(v2.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_SMALLINT:
short v3 = Marshal.ReadInt16(data);
Console.Write(v3.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_INT:
int v4 = Marshal.ReadInt32(data);
Console.Write(v4.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_BIGINT:
long v5 = Marshal.ReadInt64(data);
Console.Write(v5.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_FLOAT:
float v6 = (float)Marshal.PtrToStructure(data, typeof(float));
Console.Write(v6.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_DOUBLE:
double v7 = (double)Marshal.PtrToStructure(data, typeof(double));
Console.Write(v7.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_BINARY:
string v8 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
Console.Write(v8 + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_TIMESTAMP:
long v9 = Marshal.ReadInt64(data);
Console.Write(v9.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_NCHAR:
string v10 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
Console.Write(v10 + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_UTINYINT:
byte v12 = Marshal.ReadByte(data);
Console.Write(v12.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_USMALLINT:
ushort v13 = (ushort)Marshal.ReadInt16(data);
Console.Write(v13.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_UINT:
uint v14 = (uint)Marshal.ReadInt32(data);
Console.Write(v14.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_UBIGINT:
ulong v15 = (ulong)Marshal.ReadInt64(data);
Console.Write(v15.ToString() + "\t");
break;
case TDengineDataType.TSDB_DATA_TYPE_JSONTAG:
string v16 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
Console.Write(v16 + "\t");
break;
default:
Console.Write("nonsupport data type value");
break;
}
}
Console.WriteLine();
}
if (TDengine.ErrorNo(res) != 0)
{
Console.WriteLine($"Query is not complete, Error {TDengine.ErrorNo(res)} {TDengine.Error(res)}");
}
// exit
TDengine.FreeResult(res);
TDengine.Close(conn);
TDengine.Cleanup();
}
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)
{
Console.WriteLine("Connect to TDengine failed");
System.Environment.Exit(0);
}
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
Asynchronous query
using TDengineDriver;
using System.Runtime.InteropServices;
namespace TDengineExample
{
public class AsyncQueryExample
{
static void Main()
{
IntPtr conn = GetConnection();
QueryAsyncCallback queryAsyncCallback = new QueryAsyncCallback(QueryCallback);
TDengine.QueryAsync(conn, "select * from meters", queryAsyncCallback, IntPtr.Zero);
Thread.Sleep(2000);
TDengine.Close(conn);
TDengine.Cleanup();
}
static void QueryCallback(IntPtr param, IntPtr taosRes, int code)
{
if (code == 0 && taosRes != IntPtr.Zero)
{
FetchRowAsyncCallback fetchRowAsyncCallback = new FetchRowAsyncCallback(FetchRowCallback);
TDengine.FetchRowAsync(taosRes, fetchRowAsyncCallback, param);
}
else
{
Console.WriteLine($"async query data failed, failed code {code}");
}
}
static void FetchRowCallback(IntPtr param, IntPtr taosRes, int numOfRows)
{
if (numOfRows > 0)
{
Console.WriteLine($"{numOfRows} rows async retrieved");
DisplayRes(taosRes);
TDengine.FetchRowAsync(taosRes, FetchRowCallback, param);
}
else
{
if (numOfRows == 0)
{
Console.WriteLine("async retrieve complete.");
}
else
{
Console.WriteLine($"FetchRowAsync callback error, error code {numOfRows}");
}
TDengine.FreeResult(taosRes);
}
}
public static void DisplayRes(IntPtr res)
{
if (!IsValidResult(res))
{
TDengine.Cleanup();
System.Environment.Exit(1);
}
List<TDengineMeta> metaList = TDengine.FetchFields(res);
int fieldCount = metaList.Count;
// metaList.ForEach((item) => { Console.Write("{0} ({1}) \t|\t", item.name, item.size); });
List<object> dataList = QueryRes(res, metaList);
for (int index = 0; index < dataList.Count; index++)
{
if (index % fieldCount == 0 && index != 0)
{
Console.WriteLine("");
}
Console.Write("{0} \t|\t", dataList[index].ToString());
}
Console.WriteLine("");
}
public static bool IsValidResult(IntPtr res)
{
if ((res == IntPtr.Zero) || (TDengine.ErrorNo(res) != 0))
{
if (res != IntPtr.Zero)
{
Console.Write("reason: " + TDengine.Error(res));
return false;
}
Console.WriteLine("");
return false;
}
return true;
}
private static List<object> QueryRes(IntPtr res, List<TDengineMeta> meta)
{
IntPtr taosRow;
List<object> dataRaw = new();
while ((taosRow = TDengine.FetchRows(res)) != IntPtr.Zero)
{
dataRaw.AddRange(FetchRow(taosRow, res));
}
if (TDengine.ErrorNo(res) != 0)
{
Console.Write("Query is not complete, Error {0} {1}", TDengine.ErrorNo(res), TDengine.Error(res));
}
TDengine.FreeResult(res);
Console.WriteLine("");
return dataRaw;
}
public static List<object> FetchRow(IntPtr taosRow, IntPtr taosRes)//, List<TDengineMeta> metaList, int numOfFiled
{
List<TDengineMeta> metaList = TDengine.FetchFields(taosRes);
int numOfFiled = TDengine.FieldCount(taosRes);
List<object> dataRaw = new();
IntPtr colLengthPrt = TDengine.FetchLengths(taosRes);
int[] colLengthArr = new int[numOfFiled];
Marshal.Copy(colLengthPrt, colLengthArr, 0, numOfFiled);
for (int i = 0; i < numOfFiled; i++)
{
TDengineMeta meta = metaList[i];
IntPtr data = Marshal.ReadIntPtr(taosRow, IntPtr.Size * i);
if (data == IntPtr.Zero)
{
dataRaw.Add("NULL");
continue;
}
switch ((TDengineDataType)meta.type)
{
case TDengineDataType.TSDB_DATA_TYPE_BOOL:
bool v1 = Marshal.ReadByte(data) != 0;
dataRaw.Add(v1);
break;
case TDengineDataType.TSDB_DATA_TYPE_TINYINT:
sbyte v2 = (sbyte)Marshal.ReadByte(data);
dataRaw.Add(v2);
break;
case TDengineDataType.TSDB_DATA_TYPE_SMALLINT:
short v3 = Marshal.ReadInt16(data);
dataRaw.Add(v3);
break;
case TDengineDataType.TSDB_DATA_TYPE_INT:
int v4 = Marshal.ReadInt32(data);
dataRaw.Add(v4);
break;
case TDengineDataType.TSDB_DATA_TYPE_BIGINT:
long v5 = Marshal.ReadInt64(data);
dataRaw.Add(v5);
break;
case TDengineDataType.TSDB_DATA_TYPE_FLOAT:
float v6 = (float)Marshal.PtrToStructure(data, typeof(float));
dataRaw.Add(v6);
break;
case TDengineDataType.TSDB_DATA_TYPE_DOUBLE:
double v7 = (double)Marshal.PtrToStructure(data, typeof(double));
dataRaw.Add(v7);
break;
case TDengineDataType.TSDB_DATA_TYPE_BINARY:
string v8 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
dataRaw.Add(v8);
break;
case TDengineDataType.TSDB_DATA_TYPE_TIMESTAMP:
long v9 = Marshal.ReadInt64(data);
dataRaw.Add(v9);
break;
case TDengineDataType.TSDB_DATA_TYPE_NCHAR:
string v10 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
dataRaw.Add(v10);
break;
case TDengineDataType.TSDB_DATA_TYPE_UTINYINT:
byte v12 = Marshal.ReadByte(data);
dataRaw.Add(v12.ToString());
break;
case TDengineDataType.TSDB_DATA_TYPE_USMALLINT:
ushort v13 = (ushort)Marshal.ReadInt16(data);
dataRaw.Add(v13);
break;
case TDengineDataType.TSDB_DATA_TYPE_UINT:
uint v14 = (uint)Marshal.ReadInt32(data);
dataRaw.Add(v14);
break;
case TDengineDataType.TSDB_DATA_TYPE_UBIGINT:
ulong v15 = (ulong)Marshal.ReadInt64(data);
dataRaw.Add(v15);
break;
case TDengineDataType.TSDB_DATA_TYPE_JSONTAG:
string v16 = Marshal.PtrToStringUTF8(data, colLengthArr[i]);
dataRaw.Add(v16);
break;
default:
dataRaw.Add("nonsupport data type");
break;
}
}
return dataRaw;
}
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)
{
Console.WriteLine("Connect to TDengine failed");
Environment.Exit(0);
}
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.
More sample programs
|Sample program |Sample program description | |--------------------------------------------------------------------------------------------------------------------|------------ --------------------------------| | C#checker | Using TDengine.Connector, you can test C# Driver's synchronous writes and queries | | TDengineTest | A simple example of writing and querying using TDengine. | insertCn | Example of writing and querying Chinese characters using TDengine. | jsonTag | Example of writing and querying JSON tag type data using TDengine. | stmt | Example of parameter binding using TDengine. | schemaless | Example of writing with schemaless implemented using TDengine. |schemaless | benchmark | A simple benchmark implemented using TDengine. | async query | Example of an asynchronous query implemented using TDengine. Example of an asynchronous query | subscribe | 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 | Add asynchronous query, subscription, and other functions. Fix the binding parameter bug. |
| 1.0.3 | Add parameter binding, schemaless, JSON tag, etc. |
| 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: https://github.com/maikebing/Maikebing.EntityFrameworkCore.Taos
Frequently Asked Questions
- "Unable to establish connection", "Unable to resolve FQDN"
Usually, it's caused by an incorrect FQDN configuration. Please refer to this section in the FAQ to troubleshoot.
- 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.
