Unwind

UNWIND allows you to “unnest” a list L that has k elements in it, into a table T with k element. When using UNWIND, you need to specify an alias to refer to the elements of the unnested list, i.e., T.

We will use the example database for demonstration, whose schema and data import commands are given here.

For example, the following unnests a literal “list of strings” into multiple rows and return them:

UNWIND ["Amy", "Bob", "Carol"] AS x
RETURN x;

Output:

---------
| x     |
---------
| Amy   |
---------
| Bob   |
---------
| Carol |
---------

If the UNWINDed list L contained as elements other lists, then the output would be elements with one fewer nesting. For example, if L was a list of list of strings, after unwinding, you’d get a table of list of strings. For example:

UNWIND [["Amy"], ["Bob", "Carol"]] AS x
RETURN x;

Output:

---------------
| x           |
---------------
| [Amy]       |
---------------
| [Bob,Carol] |
---------------