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Specialized Functions

These functions perform a variety of specialized actions. You can use them with all data types.

Coalesce

Coalesce(v1,v2,v3,…,vn): Returns the first non-null value.

Important

Values passed to the Coalesce function must all be the same type (all string, all numeric, or all spatial).

Example

Coalesce(null, "oranges", "apples", null, "grapes") returns oranges.

Coalesce(oranges, apples, grapes) returns an error.

Coalesce("1", "2", "3") returns 1.

Coalesce(null, null, null) returns Null.

Coalesce(toDateTime("apples"), toDateTime(1)) returns 1899-12-31 00:00:00 because toDateTime("apples") returns null.

EscapeXMLMetacharacters

EscapeXMLMetacharacters(String): Replaces XML metacharacters with their escaped versions. There are 5 characters that are escaped.

Character

Escaped Version

"

"

'

'

<

&lt;

>

&gt;

&

&amp;

Example

EscapeXMLMetacharacters("2>1&1<2") returns 2&gt;1&amp;1&lt;2

GetVal

GetVal(index, v0,...vn): Returns the value (v0, ..., vn) specified by the 0-based index.

GetEnvironmentVariable

GetEnvironmentVariable(Name): Returns the environment variable specified in Name. To get a list of environment variables, on your machine go to Control Panel > System and Security > System > Advanced System Settings > Environment Variables. A list of system variables appears. You can use any value from this list.

Server Support

Alteryx doesn't support GetEnvironmentVariable in apps saved to Server.

Example

GetEnvironmentVariable(CommonProgramFiles) returns C:\Program Files\Common Files.

GetEnvironmentVariable(OS) returns Windows_NT.

Message

Message(messageType, message, returnValue): Use with a conditional statement to output a message to the message log and update column data with a specified value when a condition is met.

The message type and text is shown in the Results window. If logging is enabled, the output log file also resembles this information. Go to Results Window and Output Log File for more information.

Parameters

messageType: A number that corresponds to the type of message:

  • 1: Messages

  • 2: Warnings

  • 3: Errors

  • 5: Conv Errors (field conversion errors)

  • 8: Files (input)

  • 9: Files (output)

message: The text of the message, expressed as a string between quotes.

returnValue: A value to output to column data. This can be a numeric value (for example, 0), null, or a text string between quotes (for example, "False").

Example

In this example, the Message function is used within a conditional expression to output a field conversion error message and update column data with a value of "False" if given date-time values do not contain valid time data.

If [Hour] = "0" and [Minutes] = "0" then Message(5, "Invalid time in DateTime", "False") Else "True" Endif

NULL

NULL(): Returns a Null value.

RangeMedian

RangeMedian(...): Calculates the median from a series of aggregated ranges. Go to Range Median for more information.

ReadRegistryString

ReadRegistryString(Key, ValueName, DefaultValue="): Returns a value from the registry.

Soundex

Soundex(String): Returns the Soundex of String. Soundex creates a code based on the first character in the string plus 3 characters based on these items:

Character

Soundex

Non-Alpha Characters (numbers and punctuation)

-1

a, e, i, o, u, y, h, and w

Ignored unless it's the first character in the string.

b, f, p, and v

1

c, g, j, k, q, s, x, and z

2

d and t

3

l

4

m and n

5

r

6

Example

If the resulting code is only 2 or 3 characters long, Soundex uses zeros to fill out the code to 4 characters. For example, in the name Lauren, only the L, r, and n are translated (Lrn), so the resulting Soundex code is L650.

If the resulting code is more than 4 characters long, all characters after the fourth character are ignored. For example, in the name Patrick, the P, t, r, c, and k can be translated (Ptrck), but the resulting Soundex code is only 4 characters: P362.

Soundex_Digits

Soundex_Digits(String): Returns the first 4 digits or the Soundex if none.

  • If there are digits (numbers) in the String, the first 4 digits are returned.

  • If there are no digits, the Soundex code is returned.

Example String

Soundex_Digits

3825 Iris

3825

55555 Main

5555

14L Broadway

14

Commerce Street

C562

L Street

L236

TOPNIDX

TOPNIDX(N, v0, v1, ..., vn): Returns the 0-based original index position of the Nth from the maximum value upon sorting the indexed fields (v0 to vn) in descending order. Null values are ignored and N should be less than non-null parameters. With N==0, it is the same as MaxIdx(...).

  • N - Nth from the maximum value from the indexed fields

  • v0, v1, ..., vn are the indexed fields

Example

TOPNIDX(1, [IndexedField1], 5, 7) returns...

  • 0 if 5<[IndexedField1]<7

  • 1 if [IndexedField1] < 5 or [IndexedField1] is null

  • 2 if [IndexedField1] > 7

UrlEncode

UrlEncode(String): Encodes a UTF-16 string using a non-standard, UTF-16-based percent-encoding for both the original Engine and AMP.

Important

Please note that this method is no longer recommended. We recommend the new UrlEncodeUTF8 function instead.

Example

UrlEncode("C:\temp\Alteryx URL Encode") returns C:/temp/Alteryx%20URL%20Encode.

UrlEncodeUTF8

UrlEncodeUTF8(String): Encodes a string using the RFC 3986-compliant* percent-encoding. The function converts characters into UTF8-based units and it skips characters defined in the unreserved character set. Unlike the above UrlEncode function, this function doesn't skip the common URL delimiters like "/", so it's not suitable for encoding full path URLs. You should use this function to encode specific URL components, like query component parameters.

Note

*RFC 3986 is the standard for URL encoding and defines a method for encoding Unicode characters by converting them into a UTF-8 byte sequence and then representing each byte with a % (percent) sign followed by two hexadecimal digits.

Example

UrlEncodeUTF8("C:\temp\Alteryx URL Encode") returns C%3A%5Ctemp%5CAlteryx%20URL%20Encode.

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