CASE Function

Basic Usage

Example:

derive type:single value:CASE([ Qty <= 10, 'low_qty', Qty >=100, 'high_qty', 'med_qty']) as:'Qty_Eval'

Output: Generates a new Qty_Eval column, in each row contains a text string based on the evaluation of the Qty column:

• Qty <= 10 : low_qty
• Qty >= 100 : high_qty
• All other values of Qty : med_qty

Syntax and Arguments

In the following, If the testX expression evaluates to true, then the resultX value is the output.

• Test expressions are evaluated in the listed order.
• Text expressions and results are paired values in an array.
• You must include one or more test expressions.
• Each test must include a result expression. Result expression can be a literal value or an expression that evaluates to a value of a supported data type.
•  If a quoted value is included as a test expression, it is evaluated as the value to write for all values that have not yet matched a test (else expression).

CASE([test1, 'result1',test2, 'result2', testn, 'resultn','result_else'])

All of these expressions can be constants (strings, integers, or any other supported literal values) or sophisticated elements of logic, although the test expression must evaluate to a Boolean value.

For more information on syntax standards, see Language Documentation Syntax Notes.

test1, test2, testn

These parameters contain the expressions to evaluate. This expression must resolve to a Boolean (true or false) value.

Usage Notes:

result1, result2, result2, result_else

If the corresponding test expression evaluates to true, this value is written as the result.

These expressions can literals of any data type or expressions that evaluate to literals of any data type.

Usage Notes:

Examples

Example - Basic Usage

The following data represents orders received during the week. Discounts are applied to the orders based on the following rules:

• The standard discount is 5%.
• If an order is for fewer less than 10 units, then the discount is reduced by 5%.
• If an order is for more than 20 units, then the discount is increased by 5%.
• The special Friday discount is 2% more than the standard discount.

Transforms:

To determine the day of the week, you can use the following transform:

derive type:single value:WEEKDAY(Date)

derive type:single value:CASE([Qty<10, Std_Disc - 0.05, Qty>=20, Std_Disc + 0.05, weekday_Date == 5, Std_Disc + 0.02, Std_Disc]) as:'Disc'