The Row Selection options can be used to select specific rows for processing. These options specify the required rows according to values stored in their Errors column. This allows you to run MPMileage multiple times on the same database. Example applications include the computation of un-computed data rows, or to re-compute data rows that caused errors.
Select an Errors column in the Output Columns to enable these options:
The default is for the Select option to be set to all rows. This tells MPMileage to compute all rows in the database, irrespective of the error value.
The other two options (rows marked as, and rows not marked as) will enable the drop down box to the right. These options allow you to select data rows which have an error value that is equal or not equal to a specific value. I.e. rows that are "marked" with this value. The drop down box will change to include appropriate options. A custom text value can also be typed into this box.
The special value "<empty>" is interpreted as representing an empty (null length) data field.
As an example, a previous run of MPMileage may have only partially computed the dataset. You do not want to recalculate the entire dataset. Therefore you only want to select the data rows where the Error field has not yet been set - ie. it is still empty. Do this by setting the options to only "Select the rows marked as and <empty>".
As another example, a previous run of MPMileage may have created a number of errors due to mis-located or mis-named locations. You have corrected these problems, but you do not want to recalculate the data rows which were completed successfully. The successful data rows have error values marked as "Okay". Therefore, set the row selection options to "Select the rows not marked as and Okay".