Mapping initial values to target columns

You can define an initial value for an unmapped target column.

About this task

Use the Column Mappings tab to map initial values to unmapped target columns. After you have mapped your tables using the Map Tables wizard, there may be target columns that remain unmapped. Target columns can remain unmapped if the source and target column names do not match, or if there is a greater number of target columns than source columns. For these target columns, you can define an initial value such as a constant to populate the target column, or use the default value of the target column as specified in your RDBMS.

Procedure

  1. Click Configuration > Subscriptions.
  2. Select the subscription.
  3. Click the Table Mappings view and select the table mapping from the Source Table column.
  4. Right-click and select Open Details....
  5. Click the Column Mappings tab.

    You will see any unmapped target columns.

  6. Place your cursor beside the target column that you want to populate with an initial value, and click the Initial Value column.
  7. Click Set initial value button to open the Set Initial Value dialog box.
  8. Select one of the following options:
    Constant
    Populates the target column with a constant. The constant is limited to 25 characters. If you select this option, you need to enter a constant in the Constant box.
    Null
    Populates the target column with a null value. The data type of the target column must be nullable.
    Blank
    Populates the target column with a blank character. The data type of the target column must be character or a binary data type.
    Zero
    Populates the target column with a value of zero. The data type of the target column must be numeric.
    Database Default
    Populates the target column with the default specified in your RDBMS. Whenever a row gets inserted into the target table, the value that populates this column is determined from the column defaults defined in your RDBMS.
    Current Date
    Populates the target column with the current date. The data type of the target column must be datetime. If your subscription uses a CDC Replication Engine for Db2® for z/OS® as a target datastore, and you have mapped your tables using the LiveAudit mapping type, then both the before image and the after image of an update operation are populated with the same current date.
    Read Only
    Indicates that the column is Read Only and cannot be populated with an initial value.
  9. Click OK.
  10. Click Save.