Returns the linking expression for the specified relation..
<oArrayServer>:Relation(<iRelation>) Æ cRelation
<oArrayServer>:Relation(<oChildServer>) Æ cRelation
|<iRelation>||The number of the relation for which the expression is to be returned. The number corresponds to the sequence in which relations were set using the methods bArrayServer:SetRelation() or bArrayServer:SetSelectiveRelation().|
|<oChildServer>||The child server of the relation for which the expression is to be determined.|
|cRelation||The expression of the indicated relation. If the relation does not exist, the value NULL_STRING is returned.|
With the methods bArrayServer:SetRelation() and bArrayServer:SetSelectiveRelation() relations between this server and child servers can be set. bArrayServer:Relation() allows the expression of a relation can be queried at any time.