Connect to TDengine

TDengine is a time series database used to read and write data at high speed in real time. In this section, you will find information on the following topics:

• To create a TDengine

• Salient Points of TDengine

• TDengineConnections

• TDengineCommand Parameters

• TDengine Limitations

To Create a TDengine

To create a TDengine in Wyn Enterprise, navigate to the Resource Portal and follow the below instructions.

1. Click the + icon and then, select the Create Data Source option.

   
   

2. Select the TDengine option from the data source list on the left or from the icon view under the RDBMS section on the right.

   
   

3. Fill in the database configuration information. The database configuration items are described in the table below. Click the Test Connection button to verify the data source connection. Once the connection is tested and validated, you will receive a notification of a successful connection. Click the Create button to finish.

   
   

   Field	Description
   Name*	The name of the data source that you want to specify.
   Host*	A hostname or address.
   Port*	A port number, the default is 6030.
   UserName*	A user name to connect to the database.
   Password*	A password of the user.
   Database	Enter the database name or click the drop-down to select any.
   Use Configuration String (Advanced)	Use this option to connect to the data provider through a connection string. The format of the connection string is: Host=myHost;Port=myPort;Username=myUsername;Password=myPassword;Database=myDatabase

   * Required fields

4. You can view the newly added data source in the Categories tab and Data Source Document Type tab of the Resource Portal.

Salient Points

1. Currently Wyn supports only TDengine 2. x version.

2. TDengine data source is only supported in the Native Query Dataset.

• It does not support the Direct Model.

• The connector does not support the GetSchema method.

3. The following table lists the TDengine data type as compared to the C# data types.

   TDengine Datatype	C# Datatype	Dataset Datatype
   TIMESTAMP	DateTime	DateTime
   INT	int	Number
   BIGINT	long	Number
   FLOAT	float	Number
   DOUBLE	double	Number
   BINARY	byte[]	String
   TINYINT	sbyte	Number
   BOOL	bool	Boolean
   NCHAR	string	String
   JSON	string	String

   For more details on data types, refer to this article.

4. Connection configurations for TDengine: "myHost;Port=myPort;Username=myUsername;Password=myPassword;Database=myDatabase;Charset=UTF-8;Timezone=UTC-8;"

   Options supported in the connection string are listed and described in the following table,

   Property Name	Mandatory	Description
   Host	Yes	Host to be connected
   Port	Yes	Port to be connected
   Username	Yes	Username
   Password	Yes	Password
   Database	No	Database to be connected
   Charset	No	Charset set in the system
   Timezone	No	TimeZone configured in the host

   Note: Timezone does not support setting decimals using UTC and GMT methods. It supports UTF-8, UTF--8.

TDengineConnections

The GetSchema() method will return an empty table with the correct structure. The TDengine data source does not support the Preview and Table/Column mapping.

• When you preview a TDengine data source, the preview will show Can not get the data source schema because the Schema information is not available. The behavior is consistent with InfluxDB, ElasticSearchDSL data sources.

• The Use Table/Field Name Mapping option is not displayed on the Create Data Source page.

TDengineCommand Parameters

Since the Connector is using stmt to bind the parameters, the defined parameters need to be replaced in the query statement.

Parameter substitution rules are defined below in the table.

Listed below is the format of parameters in the query statement:

• The parameter must be prefixed with "@".

• The parameter must start with a letter or an underscore.

• The parameter can only contain letters, numbers, and underscores.

• If the query statement needs to use the "@" symbol to express a non-parameter statement, then you need to add "" before the "@" symbol.

  Note: CommandTimeout is not supported.

TDengine Limitations

Listed below are the limitations of TDengine.

1. You need to manually copy the corresponding driver files to the Wyn DataSet Plugin folder (default address: C:\Program Files\Wyn\Plugins\DataSet).

   Windows environment driver file is: taos.dll

   Linux environment driver file is: libtaos.so

   Configuration of tcp connections using the taos.cfg file is also supported.

2. TDengine uses FQDN (usually hostname)as the ID for a node. To make the system work, you need to configure the FQDN for the server running taosd, and configure the DNS service or hosts file on the machine where the application or TDengine CLI runs to ensure that the FQDN can be resolved. Refer to this article for more details.

3. The C# connector supports: Linux 64/Windows x64/Windows x86. Refer to this article for C# connector support.