In Talend Data Preparation, each preparation step you apply on your data is based on the previous one. As a consequence, if you already applied many preparation steps to your data, but forgot one small change at the beginning, you would not achieve the expected result.
In a preparation with many steps, you have the possibility to rearrange your preparation steps so that the changes take effect in the right order.
Let's take the example of a dataset containing customer information such as their name, email, address or the US State they live in.
Based on this dataset, a few preparation steps have already been made, including a lookup on the State column, some cleansing actions, and lastly, a correction on the State column, where one of the States was in the wrong format.
Because that last change on the State column was performed after the lookup, some information is now missing from the Region column.
You are going to take the lookup step and place it as the final step of the preparation to make sure it includes all the States.
- Point your mouse over the lookup step.
To move the lookup step from the fourth position to the first position, you
- Drag the recipe step and drop it at the top of your
- Click the up arrow on the left of your recipe step to
move it up one step at a time.
- Drag the recipe step and drop it at the top of your recipe.
Your preparation is automatically updated with the correct sequence of actions, and the Region column now includes Texas.