Your mapping model can include expressions that change
the value or the data type of a source column to be compatible with
a target column.
Before you begin
- Create a mapping model.
- Create mappings between a source and a target, or run the discover
function and accept at least one mapping.
Procedure
To add a transformation:
- Right-click a mapping model to open the mapping editor.
- Open the Expression Builder
Location |
Actions |
From the mapping editor |
Right click on a mapping line and select to
add a transformation from one or more source columns to a target column. |
From the properties view |
Right click on a mapping line and select . You can create the
transformation in the text field in the properties view or click the Expression
Builder to open the Expression Builder. |
- In the Expression Builder, double-click a child element
from the Columns field. The fully qualified
column name appears in the Transformation expression field.
- Double-click a function from the Functions field.
The function appears in the Transformation expression field.
You can manipulate the function or the column name to create a valid
statement. If a part of the statement is not valid, it is underlined
with a red wavy line if you enabled expression validation in the Workbench
preferences.
- Click OK.
Example
For example, from the mappings that are created in
Figure 1,
you can see that the matching elements do not actually match in data
type. You need to transform the source element (WORKDEPT) so that
it is compatible with the target element (DEPTNUMB):
Figure 1. Adding a transformation
Here is an example of the SQL script that you can generate from
the mapping model after adding the transformation:
SELECT ASCII(S0.WORKDEPT) AS DEPTNUMB,
...
FROM SAMP.EMPLOYEE S0;