Writing Null-Aware Expressions

When writing your scripts, be aware that field values can be null. You can use the nvl() null value function to easily define a value to use instead of null as part of any script expressions you use.

Consider the following examples:

// Assign a date three days after the PostedDate
// Use the current date instead of the PostedDate if the
// PostedDate is null
def targetDate = nvl(PostedDate,now()) + 3

// Increase an employee's custom Salary field value by 10 percent
// Use zero if current Salary is null
Salary = nvl(Salary,0) * 1.1

Tip: Both expressions you pass to the nvl() function must have the same datatype, or you will see type-checking warnings when saving your code. For example, if Salary is a number field, then it is incorrect to use an expression like nvl(Salary,’<No Salary>’) because the first expression is a number while the second expression is a string.