The function returns the first child of this member. To determine which child is first, the function considers the default order of the set of children.
For example, consider the following hierarchy:
Now consider the following query:
SELECT MEASURES.[%COUNT] ON 0, homed.zip..FIRSTCHILD ON 1 FROM patients
For another example:
SELECT MEASURES.[%COUNT] ON 0, birthd.1960.FIRSTCHILD ON 1 FROM patients