Settype Transform

Contents:

Expand all Collapse all

Our documentation site is moving!

For up-to-date documentation of Dataprep, please visit us at https://help.alteryx.com/Dataprep/.

Contents:

NOTE: Transforms are a part of the underlying language, which is not directly accessible to users. This content is maintained for reference purposes only. For more information on the user-accessible equivalent to transforms, see Transformation Reference.

Sets the data type of the specified column or columns. The column data is validated against the new data type, which can change the results of column profiling.

Type is specified as a string literal or comma-separated set of literals. For more information on valid string literals, see Valid Data Type Strings .

Tips:

Tip: You can use the settype transform to override the data type inferred for a column. However, if a new transformation step is added, the column data type is re-inferred, which may override your specific typing. You should consider applying setttype transforms as late as possible in your recipes.

When a column is set to a data type, all values in the column are validated against the new type, which might change the number of mismatched values. Some cleanup might be required. Some operations might cause the data type to be re-validated automatically.
It might be easier to set type using the column's drop-down. Selections of data type from the column drop-down are turned into recipe steps using the settype transform.
If you encounter a significant number of mismatches after you change the data type, you might find it helpful to change or revert the type to String. All data can be interpreted as a String or a list of string values. The transforms and functions for manipulating String data might be easier to use to clean up mismatched data before changing the data type to the preferred one.
Row values that do not match the new data type might be turned to null values during job execution.

Basic Usage

Single-column example:

settype col: Score type: 'Integer'

Output: Changes the data type for the Score column to Integer.

Multi-column example:

settype col: Score,studentId type: 'Integer'

Output: Changes the data type for the Score and studentId columns to Integer.

Syntax and Parameters

settype col:col1,col2 type:'string_literal'

Token	Required?	Data Type	Description
settype	Y	transform	Name of the transform
col	Y	string	Comma-separated list of columns to which to apply the specified type.
type	Y	string	String literal identifying the data type to apply to the column(s). See Valid Data Type Strings.

For more information on syntax standards, see Language Documentation Syntax Notes.

col

Identifies the column(s) to which to apply the transform. You can specify one or more columns.

Usage Notes:

Required?	Data Type
Yes	Comma-separated strings (column name or names)

type

Defines the data type that is to be applied to the transform. Type is defined as a String literal.

NOTE: When specifying a data type by name, you must use the String value listed below. The Data Type value is the display name for the type.

For a list of valid strings, see Valid Data Type Strings.

settype col: zips type:'Zipcode'

Output: Changes the data type of the zips column to Zip Code data type. All values are validated as U.S. Zip code.

Usage Notes:

Required?	Data Type
Yes	String value

Examples

Tip: For additional examples, see Common Tasks.

Example - Simple settype with date values

Source:

Here is a list of activities listed by date. Note the variation in date values, including what is clearly an invalid date. Here is the source data:

myDate, myAction
4/4/2016,Woke up at 6:30
4-4-2016,Got ready
9-9-9999,Drove kids to school
4-4-2016, Commuted to work

Transformation:

When this data is imported into the Transformer page, there are couple of immediate issues: no column headings and blank rows at the bottom. These two transformations fix that:

Transformation Name	`Rename column with row(s)`
Parameter: Option	`Use row(s) as column names`
Parameter: Type	`Use a single row to name columns`
Parameter: Row number	`1`

Transformation Name	`Filter rows`
Parameter: Condition	`Custom formula`
Parameter: Type of formula	`Custom single`
Parameter: Condition	`ismissing([myDate])`
Parameter: Action	`Delete matching rows`

For the invalid date, you can infer from the rows around it that it should be from the same date. You can make the following change to fix it:

Transformation Name	`Replace text or pattern`
Parameter: Column	`myDate`
Parameter: Find	`9-9-9999`
Parameter: Replace with	`'4-4-2016'`
Parameter: Match all occurrences	`true`

Now that the dates look fairly consistent, you can set the data type of the column to a matching Datetime format:

Transformation Name	`Change column data type`
Parameter: Columns	`myDate`
Parameter: New type	`Custom or Date/Time`
Parameter: Specify type	`'mm-dd-yy','mmddyyyy'`

Note the syntax above for specifying Datetime types. In addition to the Datetime keyword, you must specify the format type, followed by the variation of that format.

Tip: A set of supported formats and variations for Datetime are available through the column data type selector. When you select your desired Datetime format, the setttype transform is added to your recipe.

Results:

myDate	myAction
4/4/2016	Woke up at 6:30
4-4-2016	Got ready
4-4-2016	Drove kids to school
4-4-2016	Commuted to work

Example - Use merge and settype to clean up numeric data that should be treated as other data types

Unable to render {include} The included page could not be found.

See Also for Settype Transform:

Error rendering macro 'contentbylabel'

parameters should not be empty

Send Feedback

Page tree