fix: Error on missing nested SELECT.from.SELECT.from.ref

[danjoa]

• fixes [REGRESSION] db-service aggregation query throws error #1112 (comment) ?
• @patricebender pls double check

[johannes-vogel]

I think we have to add a test for this, before this release it was

...(transformedQuery.SELECT.from.ref || /* subq in from */ transformedQuery.SELECT.from.target.name),

however, i don't know how it worked ...

[hakimio]

@johannes-vogel before it was:

...(transformedQuery.SELECT.from.ref || /* subq in from */ [transformedQuery.SELECT.from.target.name]),

0828c25#diff-3406bdae94230d4664b3a51d7efa5f3807f2a43095a9089ff018c5a5faf7ca3aL803-L806

It worked because of ...[transformedQuery.SELECT.from.target.name].

[johannes-vogel]

It worked because of ...[transformedQuery.SELECT.from.target.name].

This part I understood. However, a query is not designed to have a target in SELECT.from.

[danjoa]

Exactly I wondered how that would have worked before. We really should have a test

[hakimio]

@johannes-vogel here is the answer:

if we select from <subquery> we do not have a SELECT.from.ref but the <subquery> has a .target because it has been inferred properly.

Use the name of the .target for building the correlated subquery, instead of dumping.

#709

[danjoa]

SELECT.from never has a .target.
Does it?

[patricebender]

SELECT.from never has a .target. Does it?

it has a target if we select from another query. I have re-created the issue with the following bookshop query:

http://localhost:4004/admin/Books?$apply=filter(title ne 'bar' and author/books/genre/name eq 'Drama')/groupby((author/books/genre/ID,author/books/genre/name),aggregate(price with sum as totalAmount))

this produces a query which select from another query, which has path expressions in it's where clause:
JSON.stringify(originalQuery.SELECT.from.SELECT.where, null,2)

[
  {
    "ref": [
      "title"
    ]
  },
  "!=",
  {
    "val": "bar"
  },
  "and",
  {
    "ref": [
      "author",
      "books",
      "genre",
      "name"
    ]
  },
  "=",
  {
    "val": "Drama"
  }
]

this leads to a recursive transformation of the subquery in from, resulting in multiple joins for the where condition above. Which is why SELECT.from.SELECT.from.ref is not sufficient here, as there is only a SELECT.from.SELECT.from.args. I will prepare a fix.

[patricebender]

This PR is replaced by #1126

→ added tests and thorough fix over there

[patricebender]

This PR was replaced by #1126