Column Mapping to an Existing Table
In the situations where a target table exists, column mapping cannot alter the physical target table. Although you cannot add new target columns, you can make adjustments in order to alter the source by using the . The screen appears slightly different, as there are new Populate Columns controls.
If there's a column from the source table that you no longer wish to sync, you can navigate to it in the Source Column field and blank it out. This will prevent usage of that column. You can change the Derived Fields, but you CANNOT alter the Target Table Column that the Derived Column feeds to.
If you want to have the flexibility of mapping each column individually, you can use the Clear Target and Clear Source buttons.
Clicking either button clears the respective mappings. This is generally done in the case where there is a large discrepancy between the Source Feed and the existing Target Table. Here are two examples where this feature is useful:
Example 1
Target Table A has 1000 columns, but the Source Feed has 10 columns.
In this case, you can:
1. Select Source Columns and click the Clear Target button. This will remove the Target Mappings from the screen.
2. Individually map each Target Column to the Source Column. This is accomplished by using the Drop-Down List box for the Target Column names. You will need to do this for each one of the 10 columns.
Example 2
Target Table A has 10 Columns, but the Source Feed has 10000 columns.
In this case, you can:
1. Select Target Columns and click the Clear Source button. This will remove the Source mappings from the screen.
2. Individually map each Source Column by using the Drop-Down list box for the Column Names. You will need to do this for each of the 10 columns.