Functions/Operations/Update-UserDefinedFunction.ps1

 function Update-UserDefinedFunction
{
    <#
    .SYNOPSIS
    Updates an existing user-defined function.
 
    .DESCRIPTION
    Updates an existing user-defined function.
 
    .LINK
    https://msdn.microsoft.com/en-us/library/ms186967.aspx
 
    .EXAMPLE
    Update-UserDefinedFunction -SchemaName 'rivet' 'One' 'returns tinyint begin return 1 end'
 
    Updates a user-defined function to return the number 1.
    #>
    

    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true,Position=0)]
        [string]
        # The name of the stored procedure.
        $Name,
        
        [Parameter()]
        [string]
        # The schema name of the stored procedure. Defaults to `dbo`.
        $SchemaName = 'dbo',
        
        [Parameter(Mandatory=$true,Position=1)]
        [string]
        # The store procedure's definition. Everything after the `alter function [schema].[name]` clause.
        $Definition
    )
    
    New-Object Rivet.Operations.UpdateUserDefinedFunctionOperation $SchemaName,$Name,$Definition
}