LEN Function

Returns the number of characters in a specified string. String value can be a column reference or string literal.

Basic Usage

Column reference example:

derive value:LEN(MyName)

Output: The number of characters in the value in column MyName is written to a new column.

String literal example:

derive value:LEN('Hello, World')

Output: The value 12 is written to the new column.

Syntax

derive value:LEN(column_string)

ArgumentRequired?Data TypeDescription
column_stringYstringName of the column or string literal to be applied to the function

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

column_string

Name of the column or string constant to be searched.

  • Missing string or column values generate missing string results.
  • String constants must be quoted ('Hello, World').
  • Multiple columns and wildcards are not supported.

Usage Notes:

Required?Data TypeExample Value
YesString literal or column referencemyColumn

Examples

Example - Fixed Length Strings

Source:

Your product identifiers follow a specific structure that you'd like to validate in your recipe. In the following example data, the productId column should contain values of length 6.

You can see that there is already a column containing validation errors for the ProductName column. Values in the ProductId column that are not this length should be flagged in a new column. Then, you should merge the two columns together to create a ValidationError column.

ProductNameProductIdErrProductName
Chocolate Bunnie123456Error-ProductName
Chocolate Squirl88442286Error-ProductName
Chocolate Gopher12345

Transform:

To validate the length of the values in ProductId, enter the following transform. Note that the as parameter enables you to rename the column as part of the transform.

The dataset now looks like the following:

ProductNameProductIdErrProductNameErrProductIdLength
Chocolate Bunnie123456Error-ProductName
Chocolate Squirrel88442286Error-ProductNameError-length-ProductId
Chocolate Gopher12345 Error-length-ProductId

You can blend the two error columns into a single DataValidationErrors error column using the following merge transform. Note again the use of the as parameter:

merge col:ErrProductName,ErrProductIdlength with:' ' as:'DataValidationErrors'

To clean up the data, you might want to do the following, which trims out the whitespace in the DataValidationErrors column and removes the two individual error columns:

set col:DataValidationErrors value:TRIM(DataValidationErrors)

drop col:ErrProductName

drop col:ErrProductIdLength

Results:

The final dataset should look like the following:

ProductNameProductIdDataValidationErrors
Chocolate Bunnie123456Error-ProductName
Chocolate Squirrel88442286Error-ProductName Error-length-ProductId
Chocolate Gopher12345Error-length-ProductId

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