select-scale.tql

Description

This API computes the minimum and maximum values of a given time range from a specified table and sensor at lightning speed and returns the results in CSV format. The purpose of this function is to quickly get the minimum and maximum values of a given tag within a given time range for data normalization.

The resulting format is three columns: <tagname,minvalue,minvalue,minvalue>.

It is merged into the set_minmax_value.

API module path

http://HOST:PORT/db/tql/datahub/api/v2/tql/select-scale.tql

Parameters

URL

  • Specifies the URL address where the Mahabase Neo DB is installed.
  • Example

Table

  • Specifies the name of the table that contains the data. Only a single table can be specified.
  • Example
    • table=home (O)
    • table=home.rotor (X)

name

  • Specify the Tag Name to load.
  • Set the required Tag Names after the EDA process.

start

  • Specifies the start (end) time of the extract data.
  • Note that you are extracting data up to this time, not beyond.
  • Data after the year and month can be omitted.
  • Any deviation from the given Machbase standard format will result in an error.
  • Standard format: 'Year-Month-Day-Hour-Minute-Seconds-Milliseconds-Micro-Micro-Nano'
  • Example
    • start='2024-10-31 12:33:33'
    • start='2024-10-31 12:33:33 111:222:333'
    • start='2024-10-31' (single quotation available)
    • start =1451624400000000000 (Can be specified with nano precision in epoch)
    • TO_DATE('2016-01-01 14:00:00.000000000', 'YYYY-MM-DD HH24:MI:SS.mmmuuunnn') (TO_DATE syntax allows arbitrary time formatting)
    • start=2024/11/22 (X : Date separators must be marked with -. )
    • start='2024/11/22' (X)

end

  • Specifies the end time for the extracted data. Note that you want to extract data up to and including this time, not less.
  • Other usage is the same as start.

Example Sample Code (Python)

Results

Check the entire module code.

datahub/api/v2/tql/select-scale.tql at main · machbase/datahub
All Industrial IoT DataHub with data visualization and AI source - machbase/datahub

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