Data source screen in Tableau – Building and Integrating Data Pipelines-2

Already on this screen, it is possible to fix some issues that may be present in the data.

To rename a field:

1. Click on the field you want to rename. You will notice a caret on the right of the field’s name.
2. Click on the caret, then choose Rename in the menu that will open, as shown in Figure 3.11:

Figure 3.11: Renaming a field by clicking the caret icon in Tableau

3. You will now be able to type the new name directly in the name field, as shown in Figure 3.12:

Figure 3.12: Entering a new name directly in the name field.

In this initial screen, you can also assign a variable to have a geographic or an image role (available as of Tableau 2022.4), which will allow you to create maps or bring image assets into your dashboard.

To assign one of these roles, click on the icon showing which data type every data field falls under. This will open a menu from where you will be able to choose whether to assign a geographic or an image role to the field, as shown in Figure 3.13:

Figure 3.13: Assigning a geographic or image role to a variable using the data type icon menu

Finally, already on this screen, you can change the data type to any of the types listed in the previous section. The process is similar to the geographic / image role, where clicking on the data type icon will open a menu from which you will be able to select the right data type.

In this screen, you can also start fixing some data quality issues. If, for example, the values for a specific field are scattered across different columns, you can solve the problem by following these steps:

1. Select all the columns containing the data you need.
2. On the last column you select, click on the caret.
3. Select Merge Mismatched Fields.
4. Tableau will now merge the columns and keep only non-null values.
5. Beware that if there are more values for the same row, Tableau will keep only the leftmost one.

At the same time, if you have several values in one column that should be separate, you can also address this issue in this screen with these steps:

1. Select the column containing the data.
2. Click on the caret.
3. Click on Split from the menu that opens. Tableau will split the data into several columns automatically.
4. If the automatic split does not work as required, follow the same steps as before, but click on Custom Split.
5. From this menu, specify the separators(s) in your field and whether Tableau should split all the columns, only the first, or only the last.

If you are struggling with variations in spelling or similar issues that would affect the quality of your data, you can create a group to capture all different values under one label. In order to create a group, follow these steps:

1. Select the field of interest
2. Click on the caret.
3. Select Create Group. This option will only be available for string fields.
4. A menu will open.
5. Select all the values you wish to group.
6. Click on Group.
7. Tableau will create a Group automatically.
8. Write the desired name from the group.
9. Press Enter.

All Groups can be edited at any point in time. You can tell if a data field is a group by its icon. All groups have a paperclip in their data type icon. To edit a group:

1. Right-click on its name either in the data or the visualization screen.
2. Click on Edit Group.
3. The same menu as before will open.
4. Make your changes as shown before.
5. It is possible to make several adjustments in the same group.