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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.

Creates an Object or Array of values using column names and their values as key-value pairs for one or more columns. Generated column type is determined by the into parameter.

The nest transform is the opposite of unnest, which unpacks Object data into separate columns and rows. See Unnest Transform.

Basic Usage

ItemAItemB
2233
4455

Object example:

nest col:ItemA,ItemB into:'obj' as:'myObj'

Output: See below.

ItemAItemBmyObj
2233{"ItemA":"22","ItemB","33"}
4455{"ItemA":"44","ItemB","55"}

Array example:

nest col:ItemA,ItemB into:'array' as:'myArray'

Output: Output arrays do not include the column name.

ItemAItemBmyArray
2233["22","33"]
4455["44","55"]

Parameters

nest col:column_ref [into: object|array] [as:'new_column_name']

TokenRequired?Data TypeDescription
nestYtransformName of the transform
colYstringSource column name
intoNstringData type of output column: object (default) or array
asNstringName of newly generated column

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

col

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

To specify multiple columns:

  • Discrete column names are comma-separated. 
  • Values for column names are case-sensitive.

For each listed column, a new pair of key and value columns is generated.

nest col: Qty, Amount

Output: Builds an Object of the data from the columns Qty and Amount .

Usage Notes:

Required?Data Type
YesString (column name)

into

Defines the output column type. Accepted values:

  • object
  • array

If this parameter is not specified, the output type is Object.

Usage Notes:

Required?Data Type
No (Object is default)String (data type name)

as

Name of the new column that is being generated. If the as parameter is not specified, a default name is used.

nest col: CustId,ProdId as:'masterNest'

Output: Nests the data from the columns CustId and ProdId into a new column called, masterNest.

Usage Notes:

Required?Data Type
NoString (column name)


Examples

Source:

In the following example, furniture product dimensions are stored in separate columns in cm.

CategoryNameLength_cmWidth_cmHeight_cm
benchHooska118.1174.9346.34
lampTansk30.4830.48

165.1

bookshelfBrock27.94160.02201.93
couchLoafy9522783

Transformation:

Use the nest transform to bundle the data into a single column.

Transformation Name Nest columns into Objects
Parameter: Columns Length_cm,Width_cm,Height_cm
Parameter: Nest columns to Array
Parameter: New column name 'Dimensions'

Results:

CategoryNameLength_cmWidth_cmHeight_cmDimensions
benchHooska118.1174.9346.34{"Length_cm":"118.11","Width_cm":"74.93","Height_cm":"46.34"}
lampTansk30.4830.48

165.1

{"Length_cm":"30.48","Width_cm":"30.48","Height_cm":"165.1"}
bookshelfBrock27.94160.02201.93{"Length_cm":"27.94","Width_cm":"160.02","Height_cm":"201.93"}
couchLoafy9522783{"Length_cm":"95,"Width_cm":"227","Height_cm":"83"}

See Also:

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