Tableau Interview Questions

LOD expressions are used to aggregate outside the level of detail of the view. In this case, the level of detail is defined by ZipCode. So if a developer wants to calculate the Sum by Profit at the State level, he can create a calculated field with the following LOD expression and place this calculated field in the Detail shelf.

{Fixed [State]: SUM ([Profit])}

This expression will compute at the State level. It will ignore the dimension in the view i.e. ZipCode.

Attr checks to see if there is only one value for a given field for all rows in a result set. Attr is used to aggregate the dimension.

Whenever we need to check for a single value such as if State = “NJ”, use Attr

This error occurs when a dimension is used with an aggregated function. If the dimension returns more than one row of data, this error occurs. This error can be resolved by using the ATTR function with the dimension

On the data window, navigate to the field. Right-click on the field, select Transform, and Split. The split will split the columns using the delimiter -. The split function will create two separate columns- EmpID and Name.

Tableau provides different options and functions to manage dates effectively.

-  Date property can be set by right-clicking on the data source in the Data section and select Date properties. Week Start day can be selected. Also, there is an option to specify a Fiscal Year Start Month. The Developer can also specify the Date Format to be followed in the design.

- Dates can be Discreet or Continuous. The date level of a field can be changed by dropping it into the Row or Column shelf and selecting a pill drop menu. Using this menu, dates can be changed between discreet and continuous.

-  Sometimes Dates are not interpreted correctly by Tableau and dates - comes as String or some other format. In such cases, a field can be converted to Date in Tableau. On the data window, right-click on the field and select “Change Data Type”.

-  Custom date format can be created by right-clicking on the date field and selecting Create Custom Date.

-  Dates functions available in Tableau are