Clear target cells prior to module imports

In the top-right corner of the Mapping tab, in the Import dialog, you can select:

• Clear target prior to import (default): The import deletes values in target cells and replaces them with mapped source cell values. You can then configure the options to clear the target on the tab for each dimension. There are specific options for the Time dimension that differ from those for other dimensions.
  
  The import file must contain data for the target cell values to be deleted.
• Only update imported cells: The import only clears cells that already exist in the target where there’s a matched source item.

For dimensions other than time, you can choose to either Match on names or codes or Map items manually.

Map on names or codes automatically matches source items to target items. If you want to adjust the mapping, or select items to ignore, choose to map items manually.

In the top right of the tab for the dimension you want to configure, you can configure which items the import clears. You can select:

• Mapped items in source
  Clears only those target cells mapped to a source item that exist in the source when the import runs.
• All mapped items
  Clears only those target cells mapped to a source item, even if the items no longer exist in the source. The option is unavailable if Match on names or codes is selected.
• All items
  Clears all target cells, regardless of whether they're mapped or exist in the source.

On the Time tab, under the heading What time periods to clear prior to import, you can choose Matched items only or All items.

If you select Matched items only, then where a source item is matched to a target item, the import clears the cell value:

• For time periods in the target where the matched item contains a value in the source.
• For time periods where any other matched line item contains a value in the source.

If you select All items, the import clears the cell value in the target for all time periods where a source item is matched to a target.

A source file, Fruit sales Q1, contains data for sales over a period of three months for the line items Apples and Pears. Which can be represented like this:

A Target module, Fruit sales, already has data over these time periods and also for the rest of the year. It also has an additional line item, Oranges:

If you import Fruit Sales Q1 and select to clear Matched items only, the values for all three line items are cleared for Jan-22, Feb-22, and Mar-22. The values for Oranges are cleared, even though Oranges is not a line item in the source. This is because the time periods Jan-22, Feb-22, and Mar-22 are matched to other line items in the import.

If you import Fruit Sales Q1 and select to clear All items, the values for all time periods for Apples and Pears are cleared. However, the data for Oranges is retained, as there's no line item in the source matched to this.