Tableau SQL Information Functions

Information Functions within Tableau.

A. ISNULL:
IsEmpty = ISNULL([Quantity])

This example checks if the Quantity column in the Sales table is null or empty. If the value is null, it returns TRUE; otherwise, it returns FALSE.

B. IS ERROR:
HasError = IF(ISNULL(DIV(1, 0)), TRUE, FALSE)

This example checks if the result of the DIV function, dividing 1 by 0, is an error. If an error occurs, it returns TRUE; otherwise, it returns FALSE.

C. ISSTRING:
IsTextValue = ISSTRING([CustomerName])

This example checks if the value in the CustomerName column of the Orders table is text. If the value is text, it returns TRUE; otherwise, it returns FALSE.

D. ISNUMER:
IsNumeric = IF(ISNUMBER([Amount]), TRUE, FALSE)

This example checks if the values in the Amount column of the Sales table are numbers. If the value is a number, it returns TRUE; otherwise, it returns FALSE.