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Generates a new column containing the row number as sorted by the
order parameter and optionally grouped by the
Tip: To generate row identifiers by the original order in the source data, use SOURCEROWNUMBER. See SOURCEROWNUMBER Function.
This function works with the following transforms:
Output: Generates the new column, which contains the row number of each row as ordered by the values in the
Example with grouping:
Output: Generates the new column , which contains the row number of each row as ordered by the values in the
Date column grouped by the
QTR values. For each quarter value, the row number counter resets.
For more information on the
group parameters, see Window Transform.
For more information on syntax standards, see Language Documentation Syntax Notes.
Example - Rolling window functions
This example describes how to use the rolling computational functions:
ROLLINGSUM- computes a rolling sum from a window of rows before and after the current row. See ROLLINGSUM Function.
ROLLINGAVERAGE- computes a rolling average from a window of rows before and after the current row. See ROLLINGAVERAGE Function.
ROWNUMBER- computes the row number for each row, as determined by the ordering column. See ROWNUMBER Function.
The following dataset contains sales data over the final quarter of the year.
First, you want to maintain the row information as a separate column. Since data is ordered already by the
Date column, you can use the following:
rowIdfor week of quarter.
Now, you want to extract month and week information from the
Date values. Deriving the month value:
WOQ(week of quarter).
Deriving the week-of-month value:Rename this column
WOM(week of month).
Now, you perform your rolling computations. Compute the running total of sales using the following:The
-1parameter is used in the above computation to gather the rolling sum of all rows of data from the current one to the first one. Note that the use of the
QTRcolumn for grouping, which moves the value for the
01/01/2017into its own computational bucket. This may or may not be preferred.
Rename this column
QTD (quarter to-date). Now, generate a similar column to compute the rolling average of weekly sales for the quarter:
ROLLINGAVERAGEfunction can compute fractional values, it is wrapped in the
ROUNDfunction for neatness. Rename this column
When the unnecessary columns are dropped and some reordering is applied, your dataset should look like the following:
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