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Comment: Migration of unmigrated content due to installation of a new plugin

D toc

Extracts the value from a column that is a specified number of rows before the current value.

  • The row from which to extract a value is determined by the order in which the rows are organized at the time that the transform is executed.   If you are working on a randomly generated sample of your dataset, the values that you see for this function might not correspond to the values that are generated on the full dataset during job execution.

  • If the previous value is missing or null, this function generates a missing value.
  • You can use the group and order parameters to define the groups of records and the order of those records to which this transform is applied. 
  • This function works with the following transforms:

D s

D code

window value:PREV(myNumber, 1) order:Date

Output: Generates the new column, which contains the value in the row in the myNumber column immediately preceding the current row, when ordered by Date.

D s

D code

window value:PREV(col_ref, k_integer) order: order_col [group: group_col]

ArgumentRequired?Data TypeDescription
col_refYstringName of column whose values are applied to the function
k_integerYinteger (positive)Number of rows before the current one from which to extract the value

For more information on the order and group parameters, see Window Transform.

D s lang notes


Name of the column whose values are used to extract the value that is k-integer values before the current one.

  • Multiple columns and wildcards are not supported.

D s

Required?Data TypeExample Value
YesString (column reference)myColumn


Integer representing the number of rows before the current one from which to extract the value.

  • Value must be a positive integer. For negative values, see NEXT Function.
  • k=1 represents the immediately preceding row value.
  • If k is greater than or equal to the number of values in the column, all values in the generated column are missing. If a group parameter is applied, then this parameter should be no more than the maximum number of rows in the groups.
  • If the range provided to the function exceeds the limits of the dataset, then the function generates a null value.
  • If the range of the function is valid but includes missing values, the function generates a missing, non-null value.

D s


Required?Data TypeExample Value

D s

Example - Examine prior order history

Include Page

D s also