One key aspect of working with data in Tableau is managing data types. Tableau automatically detects and assigns data types to fields in a newly uploaded dataset. However, users can modify these data types at multiple stages to suit their analysis.
There are three main ways to change the data type of a field in Tableau:
1. Change Data Type in the Data Source Page
To modify the data type from the Data Source page:
- Click the data type icon of the field you want to change.
- From the drop-down list, select the desired data type.
Example:
- Field: User Id
- Current type: Number (whole)
- New type: String
We can observe that the data type of the 'User Id' field is 'Number (whole)'. Let's change its data type from Number to String.
After this change, the User Id field is updated from Number to String and all associated values reflect the new type.
2. Change Data Type from the Data Pane
If we want to change the data type without altering the data source, we can do it from the Data pane:
- Click the data type icon of the desired field in the Data pane.
- Choose the new data type from the drop-down list.
Example:
- Field: Name
- Current type: String
- New type: Boolean
We can observe that the data type of field 'Name' is 'String'. Let's change it to Boolean.
After applying this change, the Name field is updated from String to Boolean, without modifying the original data source.
3. Change Data Type in the View
You can also modify the data type directly in a worksheet view:
- Right-click the field in the view.
- Select Change Data Type from the context menu.
- Choose the desired data type from the list.
Example:
- Field: Location
- Current type: String
- New type: Date & Time
We can observe that the data type of the 'Location' field is 'String'. Let's change it to Date & Time.
Once updated, the Location field now reflects the Date & Time type in the view.