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SQLite

Introduction

SQLite is a popular SQL database management system known for its simplicity, efficiency, and self-contained nature. Unlike traditional server-based databases, SQLite is serverless and depends solely on the file path where the database is located. It offers a rich set of features and is widely recognized for its performance, reliability, and ease of use. SQLite serves as a robust backend for a wide array of applications, from simple websites to complex transactional systems for large enterprises.

SQLiteMQTT facilitates seamless integration between SQLite and various MQTT-enabled devices and services. It supports efficient data transfer between SQLite and a MQTT broker. This asset enables users to leverage MQTT for interacting with the database, allowing for both data extraction and insertion via MQTT messages. This interaction model supports real-time data processing and enhances the capabilities of IoT applications by linking them directly with SQLite.

Features and Benefits

  • Seamless Communication: Enables seamless communication between SQLite databases and MQTT clients, streamlining the exchange of data across platforms.
  • Real-Time Query Execution: Facilitates real-time querying of the SQLite database throught MQTT messages, enabling dynamic data retrieval and manipulation.
  • Easy Integration: Simplifies the integration of SQLite with your IoT projects, making it straightforward to connect database services with various IoT devices.
  • Dynamic Query Capability: Allow users to execute SQL queries directly through MQTT, enhancing flexbility and responsiveness.

Prerequesites

Before you install and configure the asset, make sure you have the following prerequisites:

  • Basic understanding of the MQTT protocol.
  • Basic understanding of SQL and SQLite operations.
  • Access to a MQTT broker compatible with your setup.
  • MQTT Client software (such as MQTT Explorer or similar).
  • Access to the file path where your SQLite database is located.

Asset instalation

Using Coreflux HUB

Please refer the to general docs for asset installation through the Coreflux HUB.

Using Coreflux HUBLESS

Asset management and control are conducted using the MQTT protocol. Commands (payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

  1. Connect to the Coreflux MQTT Broker using your preferred client.
  2. Login using your Coreflux account: 
    -L myname@mydomain.com password
  3. Check your available assets: 
    -l
  4. Install asset: 
    -I coreflux_sqlitemqtt
  5. If there were no issues during the installation you should receive a message on the $SYS/Coreflux/Command/Output: 
    Your coreflux_sqlitemqtt was installed with version <version> with the <asset_guid>. Let the magic begin!

Asset configuration

⚠ : If a parameter is not included in your asset's configuration and it is not required, a default value will be applied. Incorrect configuration may cause the asset to not work as intended.

ℹ : This configuration is presented using a hubless setup as an example. The key takeaway is the understanding of the parameters and their significance. If you are configuring the asset via Coreflux Hub, the same parameters and configurations apply.

MQTT Parameters

The MQTTClient in the JSON configuration define how to connect to an MQTT broker, specifying the communication details. The Address and Port indicate the broker's network location (in this case, iot.coreflux.cloud on port 1883), which is where the data will be sent to or received from. The parameters also detail authentication methods and the use of TLS for secure communication. This setup determines the pathway for data exchange between the device and the MQTT broker, facilitating the monitoring or control of device operations.

Parameter Description Required Example Default Value
Port Port number on which the MQTT broker is running. Yes 1883 1883
Address IP address or hostname of the MQTT broker. Yes "iot.coreflux.cloud" "iot.coreflux.cloud"
IsAnonymous Indicates if the connection is anonymous (no username/password required). Yes true true
Username Username for authentication, if not anonymous. No "" (empty string) "" (empty string)
Password Password for authentication, if not anonymous. No "" (empty string) "" (empty string)
EnableTLS Specifies whether TLS encryption is enabled for secure communication. Yes true false

Example:

{
  "MQTTClient": {
    "Port": 1883,
    "Address": "iot.coreflux.cloud",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "EnableTLS": false
  }
}

SQL Parameters

The SQL in the JSON configuration outline the setup for SQL communication between the asset and a SQLite database. The parameter is essential for establishing a connection to the database, enabling the asset to execute queries and manage data effectively. It includes specifying the file path of the database. This configuration ensures the asset can interact with the database securely and efficiently. Additionally, the query timeout setting helps manage the perfomance of data interactions, preventing long waits in case of database response delays.

⚠ : The path defined for the Sqlite database file should be Absolute and not Relative.

Parameter Description Required Example Default Value
SQliteFilePath File path to the SQLite database. Yes "./data/database.sqlite" N/A
QueryTimeoutInSeconds Maximum duration in seconds before a query is terminated if not done. No 10 N/A

Example:

{
  "MQTTClient": {
    "Port": 1883,
    "Address": "127.0.0.1",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "EnableTLS": false
  },
  "SQL": {
    "SQliteFilePath": "./data/database.sqlite",
    "QueryTimeoutInSeconds": "10"
  }
}

Tags

Tags are crucial components that facilitate both querying from and writing to your SQLite database via MQTT interactions. Each Tag establishes a direct link between a database operation and a MQTT topic, enabling not only the execution of SQL queries but also the transmission of responses back to MQTT clients. These tags configure the specifics of the SQL operations and the MQTT communication, including the SQL query to execute, the MQTT topics for initializing requests and receiving responses, and the data formatting preferences.

Parameter Description Required Example Default Value
Name A unique identifier for the tag, up to 50 characters. Used to reference the tag within the system. Yes "TemperatureData" N/A
WriteDirection Direction of data flow (ToAll (0), ToMQTT (1), ToSQL (2)), indicating how data is communicated. Yes 2 N/A
mqttTriggerTopic MQTT Topic for triggering the query associated with the tag. Yes "request/temperature" N/A
mqttFeedbackTopic MQTT topic for publishing the results of the query. Yes "response/temperature" N/A
mqttFeedbackQos Quality of Service level for MQTT communications (0 to 2), balancing efficiency and reliability. No 1 0
mqttFeedbackRetain Indicates if the last message published to the MQTT topic should be retained by the broker. Yes true false
Query The SQL query to be executed when this Tag is triggered. Yes "SELECT temperature FROM data" N/A
OutputType The format of the output data (Raw (0), Csv (1), Json (2)), affecting how the results are formatted. Yes 2 N/A

Example:

{
  "MQTTParameters": {
    "Port": 1883,
    "Address": "127.0.0.1",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "EnableTLS": false
  },
  "SQL": {
    "SqliteFilePath": "./data/database.sqlite",
    "QueryTimeoutInSeconds": "10"
    },
  "Tags": [
    {
      "Name": "TemperatureData",
      "WriteDirection": "ToMQTT",
      "mqttTriggerTopic": "request/temperature",
      "mqttFeedbackTopic": "response/temperature",
      "mqttFeedbackQos": 1,
      "mqttFeedbackRetain": true,
      "Query": "SELECT temperature FROM data",
      "OutputType": "Json"
    },
    {
      "Name": "TemperatureData2",
      "WriteDirection": "ToMQTT",
      "mqttTriggerTopic": "request/temperature2",
      "mqttFeedbackTopic": "response/temperature2",
      "mqttFeedbackQos": 1,
      "mqttFeedbackRetain": true,
      "Query": "SELECT temperature FROM data2",
      "OutputType": "Json"
    }
  ]
}

Saving the configuration

Asset management and control are conducted using the MQTT protocol. Commands (MQTT Payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

ℹ : Configuration requires the user to be logged in and have an asset installed. If these requirements are not met, please refer to the installation section.

  1. Save configuration: 
    -assetConfigSave <asset_guid> <configuration>`

    ℹ : The asset asset_guid can be obtained by consulting the $SYS/Coreflux/Assets topic.

Example:

{"MQTTParameters":{"Port":1883,"Address":"iot.coreflux.cloud","IsAnonymous":true,"Username":"","Password":"","EnableTLS":false},"SQL":{"SqliteFilePath": "./data/database.sqlite","QueryTimeoutInSeconds":"10"},"Tags":[{"Name":"TemperatureData","WriteDirection":"ToMQTT","mqttTriggerTopic":"request/temperature","mqttFeedbackTopic":"response/temperature","mqttFeedbackQos":1,"mqttFeedbackRetain":true,"Query":"SELECT temperature FROM data","OutputType":"Json"},{"Name":"TemperatureData2","WriteDirection":"ToMQTT","mqttTriggerTopic":"request/temperature2","mqttFeedbackTopic":"response/temperature2","mqttFeedbackQos":1,"mqttFeedbackRetain":true,"Query":"SELECT temperature FROM data2","OutputType":"Json"}]}
  1. Check if the configuration was saved (optional): 
    -assetConfigLoad <asset_guid>

Using the asset

⚠ : It is important to understand that the flow of data between the broker and the device highly depends on the configuration of both the asset and the device. In case of unexpected results, please verify the configuration and/or check the logs for any possible errors.

With Coreflux HUB

Please refer the to general docs for asset installation through the Coreflux HUB.

With Coreflux HUBLESS

Asset management and control are conducted using the MQTT protocol. Commands (MQTT payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

ℹ : The asset guid can be obtained by consulting the $SYS/Coreflux/Assets topic.

Run asset

  1. Run asset:
-R <asset_guid>

Stop asset

  1. Stop asset:
-S <asset_guid>

Logs

Logs are essential for monitoring and debugging your system. They provide insight into the operation of your assets and can help identify and resolve issues promptly.

With Coreflux HUB

On Coreflux HUB, the logs are displayed in the "Log" section of the asset configuration.

With MQTT Explorer

To display logs in MQTT Explorer, follow these steps:

  1. Publish the following command to the $SYS/Coreflux/Command topic:

-addTraceLog topic=topic/to/show/log level=Error/Information/Warning messageContains=(assetID)
2. The logs will be shown on the $SYS/Coreflux/Log/Traces/topic/to/show/log topic.

Example1:

To display informational logs, use:

-addTraceLog topic=log/inf level=Information

Note : This will display the Logs "Information" of all the assets

Example2:

To display error logs, from a specific asset, use:

-addTraceLog topic=log/ethernetip/err level=Error messageContains=assetID

Note : This will display the Logs "Error" of a specific asset

Note: To display all three types of logs (Error, Information, and Warning), you will need to repeat this process three times, one for each log level. three times, one for each log level.