Utility Functions

Utility functions can be commonly used as parameters of any functions.

Context

context()

Syntax: context()

Returns context object of the script runtime.

key()

Syntax: key()

Returns the key of the current record.

value()

Syntax: value( [index] )

• index int index of the value array

Returns the whole value of the current records in array. If the index is given, it returns the element of the values.

For example, If the current value is [0, true, "hello", "world"]

• value() returns the whole value array [0, true, "hello", "world"]
• value(0) returns the first element of the value 0
• value(3) returns the last element of the value "world"

payload()

Syntax: payload()

Returns the current input stream that sent from caller of the tql script. If the tql script is called via HTTP, the result of payload() is the stream of the body content of POST request. If the tql script is called via MQTT, the payload() returns the payload of the PUBLISH message.

param()

Syntax: param( name )

• name string name of the query parameter

When the tql script is called via HTTP, the requested query parameters can be accessed by param() function.

Time

time()

Syntax: time( number|string [, duration] )

Example)

• time('now') return current time.
• time('now', '-10s50ms') return the time 10.05 seconds before from now.
• time('now -10s50ms') return the time 10.05 seconds before from now.
• time(1672531200*1000000000) returns the time of Jan-1-2023 AM 12:00:00

roundTime()

Syntax: roundTime( time, duration )

Returns rounded time.

Example)

• roundTime(time('now'), '1h')
• roundTime(key(), '1s')

parseTime()

Syntax: parseTime( time, format, timezone )

• time string time expression
• format string time format expression
• timezone tz timezone value typically use tz() function to get the demand location

Example)

• parseTime("2023-03-01 14:01:02", "DEFAULT", tz("Asia/Tokyo"))
• parseTime("2023-03-01 14:01:02", "DEFAULT", tz("local"))

tz()

Syntax: tz( name )

Returns time zone that matched with the given name

Example)

• tz('local')
• tz('UTC')
• tz('EST')
• tz("Europe/Paris")

timeformat()

Syntax: timeformat( format )

• format string

SQL(`select time, value from example limit 10`)
CSV(timeformat("DEFAULT"), tz("Asia/Seoul"))

ROWNUM	column0                column1
1       22 Aug 23 09:58 KST    0.8906962016352916
2       22 Aug 23 09:58 KST    0.8439627151061103

sqlTimeformat()

Syntax: sqlTimeformat( format )

• format string

SQL(`select time, value from example limit 10`)
CSV(sqlTimeformat("YYYY-MM-DD HH24:MI:SS.nnnnnn"), tz("Asia/Seoul"))

ROWNUM	column0	                      column1
1       2023-08-22 09:58:58.216739    0.8906962016352916
2       2023-08-22 09:58:58.226739    0.8439627151061103
3       2023-08-22 09:58:58.236739    0.7897361125403046

ansiTimeformat()

Syntax: ansiTimeformat( format )

• format string

SQL(`select time, value from example limit 10`)
CSV( ansiTimeformat("yyyy-mm-dd hh:nn:ss.ffffff"))

ROWNUM	column0	                      column1
1       2023-08-22 09:58:58.216739    0.8906962016352916
2       2023-08-22 09:58:58.226739    0.8439627151061103
3       2023-08-22 09:58:58.236739    0.7897361125403046

Others

count()

Syntax: count( array|tuple )

Returns the number of the elements.

Math

Mathematical functions. Since v8.0.6

This functions does not guarantee bit-identical results across system architectures.

An example usage of math function sqrt with MAPVALUE.