In this article, we will learn about aggregate functions, their types and uses in Tableau.
- Tableau: Tableau is a very powerful data visualization tool that can be used by data analysts, scientists, statisticians, etc. to visualize the data and get a clear opinion based on the data analysis. Tableau is very famous as it can take in data and produce the required data visualization output in a very short time.
- Case Function: Case Function is the part of Logical functions in Tableau. These functions are used to perform the logical test and return the required value when the test expression is true.
How CASE function works:
- It starts with CASE function evaluating the 1st logical expression corresponding to set/sequence of values and when the logical expression becomes True, it returns the respective specified value as result.
- If no match is found in logical expression then the value of default return expression is used.
- In case no default value is being mentioned by the user then NULL is returned.
Syntax of CASE Function:
This function finds the first that matches the given <expression> and returns the corresponding value as a result.
CASE [<expression>]
WHEN <expression> THEN <expression>
WHEN <expression> THEN <expression>
ELSE <expression>
END
Example:
- Dataset used in the given examples is Dataset.
- In this example, we simply create a new calculated field by using the CASE function on some fields.
- View new calculated field.
- Use in Visualization.
Advantages of using CASE Function:
- CASE-WHEN statements are easier to write down and comprehend.
- Due to its simplicity, for a user, it’s helpful to avoid making mistakes like referencing the incorrect field.
- CASE-WHEN statements perform faster than IF-ELSE statements.
Disadvantages of using CASE Function:
- Usage of CASE-WHEN in Tableau is extremely limited as they can’t perform Boolean logic conditions.
- CASE-WHEN in tableau only compares the expression to the precise values.
- Conditional operators like OR, AND can’t be used with CASE-WHEN.
- Using CASE-WHEN, multiple expressions can’t be evaluated during a single line.