Update node from another document

[Hazzard17h]

From documentation it's possible to update node from another file, but it seems not possible to do the same with documents:

$ echo -e "a: apples\n---\nb: bob" | yq 'select(di==0).a = select(di==1) | select(di==0)'
a: apples

[mikefarah]

By default, yq runs through documents one at a time (saves on memory), you can make it evaluate against all the documents by specifying eval-all/ea:

echo -e "a: apples\n---\nb: bob" | yq ea 'select(di==0).a = select(di==1) | select(di==0)'