DevTut

# Logical Functions

# CHOOSE

Returns the item at the specified index from a list of values. If index exceeds the bounds of values then NULL is returned.

Parameters:

  1. index: integer, index to item in values. 1-based.
  2. values: any type, comma separated list
SELECT CHOOSE (1, 'apples', 'pears', 'oranges', 'bananas') AS chosen_result

chosen_result
-------------
apples

# IIF

Returns one of two values, depending on whether a given Boolean expression evaluates to true or false.

Parameters:

  1. boolean_expression evaluated to dtermine what value to return
  2. true_value returned if boolean_expression evaluates to true
  3. false_value returned if boolean_expression evaluates to false
SELECT IIF (42 > 23, 'I knew that!', 'That is not true.') AS iif_result

iif_result
------------
I knew that!

IIF may be replaced by a CASE statement. The above example my be written as

SELECT CASE WHEN 42 > 23 THEN 'I knew that!' ELSE 'That is not true.' END AS iif_result

iif_result
------------
I knew that!

← Aggregate Functions →