[rql2sql] Handle comparison of eid on variables from an subquery
We don't want to force using 'identity' in this case which may be easily
handled by detecting variable is a `ColumnAlias` and relation is 'eid'.
Closes #15393583
Tutorials
~~~~~~~~~
We present a few tutorials of different levels. The blog building
tutorial introduces one smoothly to the basic concepts.
Then there is a photo gallery construction tutorial which highlights
more advanced concepts such as unit tests, security settings,
migration scripts.
.. toctree::
:maxdepth: 1
base/index
advanced/index
tools/windmill.rst
textreports/index
dataimport/index