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Wrangle is the domain-specific language used to build transformation recipes in Designer Cloud Enterprise Edition.
A Wrangle recipe is a sequence of transforms applied to your dataset in order to produce your results.
- A transform is a single action applied to a dataset. For most transforms, you can pass one or more parameters to define the context (columns, rows, or conditions).
- Some parameters accept one or more functions. A function is a computational action performed on one or more columns of data in your dataset.
- Recipes are built in the Transformer Page. See Transformer Page.
When you select suggestions in the Transformer Page, your selection is converted into a Wrangle command and added to your recipe.
Tip: Where possible, you should make selections in the data grid to build transform steps. These selections prompt a series of cards to be displayed at the bottom of the screen. You can select different cards to specify a basic transform for your selected data, choose a variant of that transform, and then modify the underlying Wrangle recipe as necessary. For more information, see Overview of Predictive Transformation.
For more information on the suggestion cards, see Selection Details Panel.
Some complex transforms, such as joins and unions, must be created through dedicated screens. See Transformer Page.
Wrangle vs. SQL
NOTE: Wrangle is not SQL. It is a proprietary language of data transformation, purpose-built for Designer Cloud Enterprise Edition.
While there are some overlaps between Wrangle and SQL, here are the key distinctions:
- Wrangle is a proprietary language designed for data transformation. Every supported transformation is designed to make changes to a dataset. It cannot be used to read from or write to a datastore.
- Users interact with Wrangle exclusively through the Designer Cloud application. There is no direct interaction with the language.
- SQL (Structured Query Language) is designed for querying, transforming, and writing for relational datasources. It cannot be applied to file-based datasets.
- SQL cannot be used to transform data in Designer Cloud Enterprise Edition.
Tip: Optionally, you can enable and use SQL to perform custom queries of your relational datasources. These read-only queries can be used only to import data into the product. For more information, see Enable Custom SQL Query.
Wrangle Syntax
Wrangle transforms follow this general syntax:
(transform) param1:(expression) param2:(expression)
Transform Element | Description |
---|---|
transform | A transform (or verb) is a single keyword that identifies the type of change you are applying to your dataset.
The other elements in each step are contextual parameters for the transform. Some transforms do not require parameters. |
parameter1: , parameter2: | Additional parameters may be optional or required for any transform. NOTE: A parameter is always followed by a colon. A parameter may appear only one time in a transform step. |
Common Parameters
Depending on the transform, one or more of value
, col
, and row
parameters may be used. For example, the set
transform can use all three or just value
and col
.
Transform Element | Description |
---|---|
value: | When present, the An expression can contain combinations of the following:
|
col: | When present, the Some transforms may support multiple columns as a list, as a range of columns (e.g., |
row: | When present, the row parameter defines the expression to evaluate to determine the rows on which to perform the transform. If the row expression evaluates to true for a row, the transform is performed on the row. |
group: | For aggregating transforms, such as NOTE: Transforms that use the group parameter can result in non-deterministic re-ordering in the data grid. However, you should apply the group parameter, particularly on larger datasets, or your job may run out of memory and fail.
To enforce row ordering, you can use the sort transform. For more information, see Sort Transform.
|
order: | For aggregating transforms, such as window , pivot , and derive , the order parameter can be used to specify the column by which the transform results are sorted. In the previous example, you might choose to sort your sum of sales calculation by state: order:State . |
Parameter Inputs
The following types of parameter inputs may be referenced in a transform's parameters.
Other Alteryx data types can be referenced as column references. For literal values of these data types, you can insert them into your expressions as strings. Transforms cause the resulting values to be re-inferred for their data type.
Column reference
A reference to the values stored in a column in your dataset. Columns can be referenced by the plain-text value for the column name.
Example: value
parameter references the myCol
column.
derive type:single value: myCol as:'myNewCol'
Column names with spaces or special characters in a transformation must be wrapped by curly braces.
Example: Below, srcColumn
is renamed to src Column
, which requires no braces because the new name is captured as a string literal:
rename type: manual mapping: [srcColumn, 'src Column']
After the column has been renamed with a space, it must be referenced in curly braces to be renamed back to its original name:
rename type: manual mapping: [{src Column},'srcColumn']
Functions
Some parameters accept functions as inputs. Where values or formulas are calculated, you can reference one of the dozens of functions available in Wrangle.
Example:
derive type:single value:MULTIPLY(3,2) as:'six'
Metadata variables
Wrangle supports the use of variable references to aspects of the source data or dataset. In the following example, the ABS function is applied to each column in a set of them using the $col
reference.
set col: val1,val2 value: ABS($col)
$col
returns the value of the current row. For more information on these variables, see Source Metadata References.
Nested expressions
Individual parameters within a function can be computed expressions themselves. These nested expressions can be calculated using constants, other functions, and column references.
Example: Computes a column whose only value is ten divided by three, rounded to the nearest integer (3):
derive type:single value:ROUND(DIVIDE(10,3),0) as:'three'
Integer
A valid integer value within the accepted range of values for the Integer datatype. For more information, see Supported Data Types.
Example: Generates a column called, my13
which is the sum of the Integer values 5
and 8
:
derive type:single value: (5 + 8) as:'my13'
Decimal
A valid floating point value within the accepted range of values for the Decimal datatype. For more information, see Supported Data Types.
Example: Generates a column of values that computes the approximate circumference of the values in the diameter
column:
derive type:single value: (3.14159 * diameter) as: 'circumference'
Boolean
A true
or false
value.
Example: If the value in the order
column is more than 1,000,000, then the value in the bigOrder
column is true
.
derive type:single value:IF(order > 1000000, true, false) as:'bigOrder'
String
A string literal value is the baseline datatype. String literals must be enclosed in single quotes.
Example: Creates a column called, StringCol
containing the value myString
.
derive type:single value:'myString' as:'StringCol'
Alteryx pattern
Designer Cloud Enterprise Edition supports a special syntax, which simplifies the generation of matching patterns for string values.
Patterns must be enclosed in accent marks ( `MyPattern`
). For more information, see Text Matching.
Example: Extracts up to 10 values from the MyData
column that match the basic pattern for social security numbers (XXX-XX-XXXX
):
extract col: MyData on:`%{3}-%{2}-%{4}` limit:10
Regular expression
Regular expressions are a common standard for defining matching patterns. Regex is a very powerful tool but can be easily misconfigured.
Regular expressions must be enclosed in slashes ( /MyPattern/
).
Example: Deletes all two-digit numbers from the qty
column:
replace col: qty on: /^\d$|^\d\d$/ with: '' global: true
Datetime
A valid date or time value that matches the requirements of the Datetime datatype. See Supported Data Types.
Datetime values can be formatted with specific formatting strings. See DATEFORMAT Function.
Example: Generates a new column containing the values from the myDate
column reformatted in yyyymmdd
format:
derive type:single value:DATEFORMAT(myDate, 'yyyymmdd')
Array
A valid array of values matching the Array data type.
Example:
[0,1,2,3,4,5,6,7,8]
See Supported Data Types.
Example: Generates a column with the number of elements in the listed array (7
):
derive type:single value: ARRAYLEN('["red", "orange", "yellow", "green", "blue", "indigo", "violet"]')
Object
A valid set of values matching the Object data type.
Example:
{"brand":"Subaru","model":"Impreza","color","green"}
See Supported Data Types.
Example: Generates separate columns for each of the specified keys in the object ( brand
, model
, color
), containing the corresponding value for each row:
unnest col:myCol keys:'brand','model','color'
Interactions between Wrangle and the Application
- As you build Wrangle steps in the Transform Builder, your syntax is validated for you. You cannot add steps containing invalid syntax.
- Error messages are reported back to the application, so you can make immediate modifications to correct the issue.
- Type-ahead support can provide guidance to the supported transforms, functions, and column references.
- For more information, see Transform Builder.
- When you have entered a valid transform step, the results are previewed for you in the data grid.
This preview is generated by applying the transform to the sample in the data grid.
NOTE: The generated output applies only to the values displayed in the data grid. The function is applied across the entire dataset only during job execution.
- If the previewed transform is invalid, the data grid is grayed out.
- For more information, see Transform Preview.
- When you add the transform to your recipe:
- It is applied to the sample in the application, and the data grid is updated to the current state.
- Column histograms are updated with new values and counts.
- Column data types may be re-inferred for affected columns.
- Making changes:
- You can edit any transform step in your recipe whenever needed.
- When you edit a transform step in your recipe, the context of the data grid is changed to display the state of your data up to the point of previewing the step you're editing.
- All subsequent steps are still part of the recipe, but they are not applied to the sample yet.
- You can insert recipe steps between existing steps.
- When you delete a recipe step, the state remains at the point where the step was removed.
- You can insert a new step if needed.
- When you complete your edit, select the final step of the recipe, which displays the results of all of your transform steps in the data grid. Your changes may cause some recipe steps to become invalid.
- See Recipe Panel.
- You can edit any transform step in your recipe whenever needed.
Transforms
A transform , or verb, is an action applied to rows or columns of your data. Transforms are the essential set of changes that you can apply to your dataset. For more information, see Transforms.
Function Categories
A function is an action that is applied to a set of values as part of a transform step. Functions can apply to the values in a transform for specific data types, such as strings, or to types of transforms, such as aggregate and window function categories. A function cannot be applied to data without a transform.
Function Category | Description |
---|---|
These functions are used to perform aggregation calculations on your data, such as sum, mean, and standard deviation. | |
Comparison Functions | Comparison functions enable evaluation between two data elements, which are typically nested (Object or Array) elements. |
Math Functions | Perform computations on your data using a variety of math functions and numeric operators. |
Date Functions | Use these functions to extract data from or perform operations on objects of Datetime data type. |
String Functions | Manipulate strings, including finding sub-strings within a string. |
Nested Functions | These functions are designed specifically to assist in wrangling nested data, such as Objects, Arrays, or JSON elements. |
Type Functions | Use the Type functions to identify valid, missing, mismatched, and null values. |
Window Functions | The Window functions enable you to perform calculations on relative windows of data within your dataset. |
Other Functions | Miscellaneous functions that do not fit into the other categories |
Operator Categories
An operator is a single character that represents an arithmetic function. For example, the Plus sign (+
) represents the add function.
Operator Category | Description |
---|---|
Logical Operators | and, or, and not operators |
Numeric Operators | Add, subtract, multiply, and divide |
Comparison Operators | Compare two values with greater than, equals, not equals, and less than operators |
Ternary Operators | Use ternary operators to create if/then/else logic in your transforms. |
Documentation
Documentation for Wrangle is also available through Designer Cloud Enterprise Edition. Select Help menu > Product Docs.
Tip: When searching for examples of transforms and functions, try using the following forms for your search terms within the Product Docs site:
- Transforms:
wrangle_transform_NameOfTransform
- Functions:
wrangle_function_NameOfFunction
All Topics
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