.alter function command

Artikkeli
08/12/2024

Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer

Alters an existing function and stores it inside the database metadata. Rules for parameter types and CSL statements are the same as for let statements.

Permissions

You must have at least Function Admin permissions to run this command. The principal that creates the function is automatically made a Function Admin.

Syntax

.alter function [ with ( propertyName = propertyValue [, ...])] functionName(parameters) { body }

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
functionName	`string`	✔️	The name of the function to alter.
propertyName, propertyValue	`string`		A comma-separated list of key-value property pairs. See supported properties.
parameters	`string`		A comma-separated list of parameters required by the function. The format for each parameter must be ParameterName`:`ParameterDataType.
body	`string`	✔️	Zero or more `let` statements followed by a valid CSL expression that is evaluated upon function invocation.

Note

If the function doesn't exist, an error is returned. For creating a new function, see .create function
Not all Kusto types are supported in let statements. Supported types are: string, long, datetime, timespan, and double.

Supported properties

Name	Type	Description
`docstring`	`string`	A description of the function for UI purposes.
`folder`	`string`	The name of a folder used for UI functions categorization.
`view`	`bool`	Designates this function as a stored view. Stored views can participate in search and union * scenarios. For more information, see Views.
`skipvalidation`	`bool`	Determines whether to run validation logic on the function and fails the process if the function isn't valid. The default is `false`.

Example

The following example modifies the MyFunction2 function with a description (docstring), folder, and defines the MyLimit parameter.

.alter function
with (docstring = 'Demo function with parameter', folder='MyFolder')
MyFunction2(myLimit: long)  
{StormEvents | take myLimit}

Name	Parameters	Body	Folder	DocString
MyFunction2	(myLimit: long)	{StormEvents \| take myLimit}	MyFolder	Demo function with parameter

Jaa