In this tutorial, you’ll explore how to use APL in Axiom’s Query tab to run queries using Tabular Operators, Scalar Functions, and Aggregation Functions.
Prerequisites
Overview of APL
Every query, starts with a dataset embedded in square brackets, with the starting expression being a tabular operator statement. The query’s tabular expression statements produce the results of the query.
Before you can start writing tabular operators or any function, the pipe (|) delimiter starts the query statements as they flow from one function to another.
Commonly used Operators
To run queries on each function or operator in this tutorial, click the Run in Playground button.
summarize: Produces a table that aggregates the content of the dataset.
The following query returns the count of events by time
['github-push-event']
| summarize count() by bin_auto(_time)
Run in Playground
You can use the aggregation functions with the summarize operator to produce different columns.
Top 10 GitHub push events by maximum push id
['github-push-event']
| summarize max_if = maxif(push_id, true) by size
| top 10 by max_if desc
Run in Playground
Distinct City count by server datacenter
['sample-http-logs']
| summarize cities = dcount(['geo.city']) by server_datacenter
Run in Playground
The result of a summarize operation has:
where: Filters the content of the dataset that meets a condition when executed.
The following query filters the data by method and content_type:
['sample-http-logs']
| where method == "GET" and content_type == "application/octet-stream"
| project method , content_type
Run in Playground
count: Returns the number of events from the input dataset.
['sample-http-logs']
| count
Run in Playground
Summarize count by time bins in sample HTTP logs
['sample-http-logs']
| summarize count() by bin_auto(_time)
Run in Playground
project: Selects a subset of columns.
['sample-http-logs']
| project content_type, ['geo.country'], method, resp_body_size_bytes, resp_header_size_bytes
Run in Playground
take: Returns up to the specified number of rows.
['sample-http-logs']
| take 100
Run in Playground
The limit operator is an alias to the take operator.
['sample-http-logs']
| limit 10
Run in Playground
Scalar Functions
The following query extracts the JSON elements from an array:
['sample-http-logs']
| project parsed_json = parse_json( "config_jsonified_metrics")
Run in Playground
replace_string(): Replaces all string matches with another string.
['sample-http-logs']
| extend replaced_string = replace_string( "creator", "method", "machala" )
| project replaced_string
Run in Playground
split(): Splits a given string according to a given delimiter and returns a string array.
['sample-http-logs']
| project split_str = split("method_content_metrics", "_")
| take 20
Run in Playground
strcat_delim(): Concatenates a string array into a string with a given delimiter.
['sample-http-logs']
| project strcat = strcat_delim(":", ['geo.city'], resp_body_size_bytes)
Run in Playground
['sample-http-logs']
| extend based_index = indexof( ['geo.country'], content_type, 45, 60, resp_body_size_bytes ), specified_time = bin(resp_header_size_bytes, 30)
Run in Playground
Regex Examples
['sample-http-logs']
| project remove_cutset = trim_start_regex("[^a-zA-Z]", content_type )
Run in Playground
Finding logs from a specific City
['sample-http-logs']
| where tostring(geo.city) matches regex "^Camaquã$"
Run in Playground
Identifying logs from a specific user agent
['sample-http-logs']
| where tostring(user_agent) matches regex "Mozilla/5.0"
Run in Playground
Finding logs with response body size in a certain range
['sample-http-logs']
| where toint(resp_body_size_bytes) >= 4000 and toint(resp_body_size_bytes) <= 5000
Run in Playground
Finding logs with user agents containing Windows NT
['sample-http-logs']
| where tostring(user_agent) matches regex @"Windows NT [\d\.]+"
Run in Playground
['sample-http-logs']
| where toint(resp_header_size_bytes) == 31
Run in Playground
Finding logs with specific request duration
['sample-http-logs']
| where toreal(req_duration_ms) < 1
Run in Playground
Finding logs where TLS is enabled and method is POST
['sample-http-logs']
| where tostring(is_tls) == "true" and tostring(method) == "POST"
Run in Playground
Array functions
array_concat(): Concatenates a number of dynamic arrays to a single array.
['sample-http-logs']
| extend concatenate = array_concat( dynamic([5,4,3,87,45,2,3,45]))
| project concatenate
Run in Playground
array_sum(): Calculates the sum of elements in a dynamic array.
['sample-http-logs']
| extend summary_array=dynamic([1,2,3,4])
| project summary_array=array_sum(summary_array)
Run in Playground
Conversion functions
['sample-http-logs']
| extend dated_time = todatetime("2026-08-16")
Run in Playground
dynamic_to_json(): Converts a scalar value of type dynamic to a canonical string representation.
['sample-http-logs']
| extend dynamic_string = dynamic_to_json(dynamic([10,20,30,40 ]))
Run in Playground
String Operators
We support various query string, logical and numerical operators.
In the query below, we use the contains operator, to find the strings that contain the string -bot and [bot]:
['github-issue-comment-event']
| extend bot = actor contains "-bot" or actor contains "[bot]"
| where bot == true
| summarize count() by bin_auto(_time), actor
| take 20
Run in Playground
['sample-http-logs']
| extend user_status = status contains "200" , agent_flow = user_agent contains "(Windows NT 6.4; AppleWebKit/537.36 Chrome/41.0.2225.0 Safari/537.36"
| where user_status == true
| summarize count() by bin_auto(_time), status
| take 15
Run in Playground
Hash Functions
-
hash_md5(): Returns an MD5 hash value for the input value.
-
hash_sha256(): Returns a sha256 hash value for the input value.
-
hash_sha1(): Returns a sha1 hash value for the input value.
['sample-http-logs']
| extend sha_256 = hash_md5( "resp_header_size_bytes" ), sha_1 = hash_sha1( content_type), md5 = hash_md5( method), sha512 = hash_sha512( "resp_header_size_bytes" )
| project sha_256, sha_1, md5, sha512
Run in Playground
List all unique groups
['sample-http-logs']
| distinct ['id'], is_tls
Run in Playground
Count of all events per service
['sample-http-logs']
| summarize Count = count() by server_datacenter
| order by Count desc
Run in Playground
Change the time clause
['github-issues-event']
| where _time == ago(1m)
| summarize count(), sum(['milestone.number']) by _time=bin(_time, 1m)
Run in Playground
Rounding functions
-
floor(): Calculates the largest integer less than, or equal to, the specified numeric expression.
-
ceiling(): Calculates the smallest integer greater than, or equal to, the specified numeric expression.
-
bin(): Rounds values down to an integer multiple of a given bin size.
['sample-http-logs']
| extend largest_integer_less = floor( resp_header_size_bytes ), smallest_integer_greater = ceiling( req_duration_ms ), integer_multiple = bin( resp_body_size_bytes, 5 )
| project largest_integer_less, smallest_integer_greater, integer_multiple
Run in Playground
Truncate decimals using round function
['sample-http-logs']
| project rounded_value = round(req_duration_ms, 2)
Run in Playground
Truncate decimals using floor function
['sample-http-logs']
| project floor_value = floor(resp_body_size_bytes), ceiling_value = ceiling(req_duration_ms)
Run in Playground
HTTP 5xx responses (day wise) for the last 7 days - one bar per day
['sample-http-logs']
| where _time > ago(7d)
| where req_duration_ms >= 5 and req_duration_ms < 6
| summarize count(), histogram(resp_header_size_bytes, 20) by bin(_time, 1d)
| order by _time desc
Run in Playground
Implement a remapper on remote address logs
['sample-http-logs']
| extend RemappedStatus = case(req_duration_ms >= 0.57, "new data", resp_body_size_bytes >= 1000, "size bytes", resp_header_size_bytes == 40, "header values", "doesntmatch")
Run in Playground
Advanced aggregations
In this section, you will learn how to run queries using different functions and operators.
['sample-http-logs']
| extend prospect = ['geo.city'] contains "Okayama" or uri contains "/api/v1/messages/back"
| extend possibility = server_datacenter contains "GRU" or status contains "301"
| summarize count(), topk( user_agent, 6 ) by bin(_time, 10d), ['geo.country']
| take 4
Run in Playground
Searching map fields
['otel-demo-traces']
| where isnotnull( ['attributes.custom'])
| extend extra = tostring(['attributes.custom'])
| search extra:"0PUK6V6EV0"
| project _time, trace_id, name, ['attributes.custom']
Run in Playground
['sample-http-logs']
| where _sysTime > ago(1d)
| summarize count() by method
Run in Playground
Return different values based on the evaluation of a condition
['sample-http-logs']
| extend MemoryUsageStatus = iff(req_duration_ms > 10000, "Highest", "Normal")
Run in Playground
Working with different operators
['hn']
| extend superman = text contains "superman" or title contains "superman"
| extend batman = text contains "batman" or title contains "batman"
| extend hero = case(
superman and batman, "both",
superman, "superman ",
batman, "batman ",
"none")
| where (superman or batman) and not (batman and superman)
| summarize count(), topk(type, 3) by bin(_time, 30d), hero
| take 10
Run in Playground
['sample-http-logs']
| summarize flow = dcount( content_type) by ['geo.country']
| take 50
Run in Playground
Get the JSON into a property bag using parse-json
example
| where isnotnull(log)
| extend parsed_log = parse_json(log)
| project service, parsed_log.level, parsed_log.message
Get average response using project keep function
['sample-http-logs']
| where ['geo.country'] == "United States" or ['id'] == 'b2b1f597-0385-4fed-a911-140facb757ef'
| extend systematic_view = ceiling( resp_header_size_bytes )
| extend resp_avg = cos( resp_body_size_bytes )
| project-away systematic_view
| project-keep resp_avg
| take 5
Run in Playground
Combine multiple percentiles into a single chart in APL
['sample-http-logs']
| summarize percentiles_array(req_duration_ms, 50, 75, 90) by bin_auto(_time)
Run in Playground
Combine mathematical functions
['sample-http-logs']
| extend tangent = tan( req_duration_ms ), cosine = cos( resp_header_size_bytes ), absolute_input = abs( req_duration_ms ), sine = sin( resp_header_size_bytes ), power_factor = pow( req_duration_ms, 4)
| extend angle_pi = degrees( resp_body_size_bytes ), pie = pi()
| project tangent, cosine, absolute_input, angle_pi, pie, sine, power_factor
Run in Playground
['github-issues-event']
| where actor !endswith "[bot]"
| where repo startswith "kubernetes/"
| where action == "opened"
| summarize count() by bin_auto(_time)
Run in Playground
Change global configuration attributes
['sample-http-logs']
| extend status = coalesce(status, "info")
Run in Playground
Set defualt value on event field
['sample-http-logs']
| project status = case(
isnotnull(status) and status != "", content_type,
"info"
)
Run in Playground
['otel-demo-traces']
| extend amount = ['attributes.custom']['app.payment.amount']
| where isnotnull( amount)
| project _time, trace_id, name, amount, ['attributes.custom']
Run in Playground
Filtering GitHub issues by label identifier
['github-issues-event']
| extend data = tostring(labels)
| where labels contains "d73a4a"
Run in Playground
Aggregate trace counts by HTTP method attribute in custom map
['otel-demo-traces']
| extend httpFlavor = tostring(['attributes.custom'])
| summarize Count=count() by ['attributes.http.method']
Run in Playground
