Caché ObjectScript Reference - InterSystems Documentation

Caché ObjectScript CommandsMERGEMerges global nodes or subtrees from source into destination.MERGE:pc mergeargument,...M:pc mergeargument,...where mergeargument is:destination=sourceArgumentspcdestination and sourceOptional — A postconditional expression.Local variables, process-private globals, or globals to bemerged.DescriptionMERGE destination=source copies source into destination and all descendants of sourceinto descendants of destination. It does not modify source, or kill any nodes in destination.MERGE simplifies the copying of a sub-tree (multiple subscripts) of a variable to anothervariable. Either variable can be a local variable, a process-private global, or a global. A subtreeis all variables that are descendants of a specified variable. MERGE offers a one-commandalternative to the current technique for doing sub-tree copy: a series of SET commands with$ORDER references.MERGE returns a error if the source and destination have a parent-childrelationship.The MERGE command can take longer than most other Caché ObjectScript commands toexecute. As a result, it is more prone to interruption. The effect of interruption is implementation-specific.Under Caché, an interruption may cause an unpredictable subset of the sourceto have been copied to the destination subtree.ArgumentspcAn optional postconditional expression. Caché executes the MERGE command if the postconditionalexpression is true (evaluates to a non-zero numeric value). Caché does not execute90 Caché ObjectScript Reference