Decision variables and placeholders

When you call a Decision, you can pass values to it as input parameters. In the Decision itself, you can pass values retrieved by Decision SQL to the decision's Yes Action and No Action scripts. You can also choose to store a value in a global variable for continued use. Some script constructs require that a value is stored in such a global variable.

Passing values to decisions as input parameters

When you call a Decision, you can pass values to it as the second, third... argument of the ActionDecision() action:

ActionDecision( MY_DECISION, 'Table1', 776 )

Each value passed is referenceable by a numbered placeholder ( :1, :2 ...) in the decision's Decision SQL. Before the SQL statement is executed, each :1 placeholder is substituted by the value passed in first place (in the example, the Table1 string), each :2 placeholder by the next value (in the example, the number 776), and so on.

Passing values between SQL and action scripts

After a decision's Decision SQL is executed, the output values from the SELECT clause may be passed to the Yes Action and No Action scripts. Every time the :1 placeholder appears in these scripts, it is substituted by the first output value from the SELECT list for the retrieved row currently being processed. Each :2 placeholder is substituted by the second output value from the SELECT list, and so on.

Global variables

In the Yes Action and No Action scripts, instead of picking up an output value from the Decision SQL in a numbered placeholder (:1, :2...), you can take the intermediary step of first storing the value in a global variable. The ResourceFileUpdate() action allows you to do this. The syntax for storing a value in this way is:

ResourceFileUpdate( 'variable-name : variable-value' )

The stored value is now named and may be accessed repeatedly by name until it is cleared or reset. The syntax for accessing a stored value is:

:"variable"

One special reason for using global variables is that you need them to substitue values in SqlScript() statements. See the next section in this help topic for details.

The general pattern for catching a value in a global variable is:

(Decision SQL:)

SELECT value1
, value2 ...

(Yes Action:)

ResourceFileUpdate( 'name1:' ) || :1
ResourceFileUpdate( 'name2:' ) || :2

... :"name1" ...
... :"name2" ...

An example of this pattern is:

(Decision SQL:)

SELECT  T_RDMI_AUTOMATION_SERVER
,       T_RDMI_JAVA_COMPONENT,
FROM    T_RDMI_COMPONENT
WHERE   COMPONENT_NAME= :1

(Yes Action:)

ResourceFileUpdate( 'global.automation:' || :1 )
ResourceFileUpdate( 'global.java:' || :2 )

SqlScript(
  UPDATE  appcomponent
  SET     processed = 'Y'
  WHERE   autom = :"global.automation"
  AND     java_class = :"global.automation"
)

Global variables in SqlScript()

In the Yes Action and No Action scripts, you can perform data manipulation. The SqlScript() action allows you to do this, but if you want to substitute variables in the SQL statement before executing it, you need to cast them in global variables because substitution placeholders of type :1, :2 will not be resolved by SqlScript():

(Decision SQL:)

SELECT  :1
,       :2
,       typename
FROM    t_e_type
WHERE   application_id = :2
AND     is_class ='Y'
AND     typename IN
(
   SELECT page_name
   FROM   t_page_in_page_set pps
   ,      t_e_type tt
   WHERE  pps.page_set_name = :1
   AND    tt.id = :2
   AND    pps.application =  tt.typename
)

(Yes Action:)

ResourceFileUpdate('windowToList:' || :3)

SqlScript(
  INSERT INTO windows_in_set( name )
  SELECT :windowToList
  FROM   dual
  WHERE NOT EXISTS(
    SELECT ''
    FROM   windows_in_set
    WHERE  name = :windowToList
  )
)