Following is the order of evaluation:
- Host setup script will be executed first
- All Common parameters, that is, included, are evaluated
- All Sandbox parameters are evaluated
- The project script – project-start. ksh is executed
- All form parameters are evaluated
- Graph parameters are evaluated
- The End Script of the graph is executed
first_defined -
Returns the first defined (non-NULL) value from among the input arguments. The input expressions must all be of the same or compatible types.
Syntax
object first_defined(expr [ , expr ... ] )
Usage -
- > You must specify at least two expressions as arguments for this function.
- > This function is useful in assigning default values to input fields whose values are NULL. The function does the following:
- > Checks each input value to see if the value is defined.
- > Stops at the first defined value.
- > Returns the first defined value.
- > If all arguments evaluate NULL, this function returns NULL.
This function is equivalent to the SQL function COALESCE and similar to the older Oracle function NVL.
Example 1 -
first_defined(expr1 = (decimal(3))1.1, expr2 = "jan", expr3 = "feb", expr4 = "mar")
(Types long and decimal are compatible in the preceding expression.) The function returns the following result:
"1.1"
Example 2 -
In this example, some of the function’s arguments are NULL:
first_defined(NULL, 42, NULL, 43)
The function returns the following result:
42
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