Wikipedia
FLWOR
The programming language XQuery defines FLWOR (pronounced 'flower') as an expression that supports iteration and binding of variables to intermediate results. FLWOR is an acronym: FOR, LET, WHERE, ORDER BY, RETURN. FLWOR is loosely analogous to SQL's SELECT-FROM-WHERE and can be used to provide join-like functionality to XML documents.
- for creates a sequence of nodes
- let binds a sequence to a variable
- where filters the nodes on a boolean expression
- order by sorts the nodes
- return gets evaluated once for every node