Conditions that test for existence

The following definitions cover operators that test for specified data.

there are

The operator there are tests whether there is a specific number of business terms of a certain type in the data from the application that calls the decision.

The following condition checks for two customers:

if 
   there are 2 customers in customers
then... 

You can use the operator where to specify more conditions to apply to business terms.

The following rule condition is only true if there are 10 customers, and if each customer is a member of the Gold category:

if
   there are 10 customers in customers where the category of each customer is Gold, 
then... 

there are at least and there are at most

The following operators check whether data contains more or fewer instances of a business term than a specified number:

• there are at least: The condition is true if the number of occurrences of the business term is greater than or equal to the specified number.

• there are at most: The condition is true if the number of occurrences of the business term is less than or equal to the specified number.

The following condition checks that there are no more than three Gold customers:

if 
	there are at most 3 customers in customers
		where the category of each customer is Gold, 
then... 

The following condition checks whether there are more Gold customers than Silver customers. The rule starts by defining the following variables:

• silver customers: The list of customers in the Silver category.

• silver count: The number of customers in the Silver category.

The rule then uses these variables to compare the number of Gold customers with the number of Silver customers:

definitions 
	set 'silver customers' to all customers in customers
		where the category of each customer is Silver; 
	set 'silver count' to the number of elements in 'silver customers';
if 
	there are at least ('silver count' + 1) customers in customers 
		where the category of each customer is Gold, 
then... 

there is at least one

The operator there is at least one checks that there is at least one instance of a business term in the data from the application that calls the decision. The data can contain more than one instance of the business term.

The following condition looks for at least one customer object:

if 
	there is at least one customer in customers
then... 

The following example checks for at least one senior Gold customer:

definitions
   set 'gold customers' to all customers in customers
      where the category of each customer is Gold; 
if 
   there is at least one customer in 'gold customers' 
      where the age of this customer is at least 65, 
then...