APPLY

APPLY
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[attrname := ] APPLY (dataset, actionlist [ , BEFORE( actionlist ) ] [ , AFTER( actionlist [, UNORDERED | ORDERED( bool ) ] [, STABLE | UNSTABLE ] [, PARALLEL [ ( numthreads ) ] ] [, ALGORITHM( name ) ]) ] )

attrname	Optional. The action name, which turns the action into an attribute definition, therefore not executed until the attrname is used as an action.
dataset	The set of records to apply the action to. This must be the name of a physical dataset of a type that supports this operation.
actionlist	A comma-delimited list of the operations to perform on the dataset. Typically, this is an external service (see SERVICE Structure). This may not be an OUTPUT or any function that triggers a child query.
BEFORE	Specifies executing the enclosed actionlist before the first dataset row is processed. Not yet implemented in Thor, valid only in hthor and Roxie.
AFTER	Specifies executing the enclosed actionlist after the last dataset row is processed. Not yet implemented in Thor, valid only in hthor and Roxie.
UNORDERED	Optional. Specifies the output record order is not significant.
ORDERED	Specifies the significance of the output record order.
bool	When False, specifies the output record order is not significant. When True, specifies the default output record order.
STABLE	Optional. Specifies the input record order is significant.
UNSTABLE	Optional. Specifies the input record order is not significant.
PARALLEL	Optional. Try to evaluate this activity in parallel.
numthreads	Optional. Try to evaluate this activity using numthreads threads.
ALGORITHM	Optional. Override the algorithm used for this activity.
name	The algorithm to use for this activity. Must be from the list of supported algorithms for the SORT function's STABLE and UNSTABLE options.

The APPLY action performs all the specified actions in the actionlist on each record of the nominated dataset. The actions execute in the order they appear in the actionlist.

Example:

EXPORT x :=  SERVICE
  echo(const string src):library='myfuncs',entrypoint='rtlEcho';
END;
APPLY(person,x.echo(last_name + ':' + first_name));
 // concatenate each person's lastname and firstname and echo it

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