### Description
Each Backend executes queries against the database in a slightly different stack: Postgres uses its own `TXeT`, MSSQL uses a variant of it, BigQuery is simply in `ExceptT QErr IO`... To accommodate those variations, we had originally introduced an `ExecutionMonad b` type family in `BackendExecute`, allowing each backend to describe its own stack. It was then up to that backend's `BackendTransport` instance to implement running said stack, and converting the result back into our main app monad.
However, this was not without complications: `TraceT` is one of them: as it usually needs to be on the top of the stack, converting from one stack to the other implies the use `interpTraceT`, which is quite monstrous. Furthermore, as part of the Entitlement Services work, we're trying to move to a "Services" architecture in which the entire engine runs in one base monad, that delegates features and dependencies to monad constraints; and as a result we'd like to minimize the number of different monad stacks we have to maintain and translate from and to in the codebase.
To improve things, this PR changes `ExecutionMonad b` from an _absolute_ stack to a _relative_ one: i.e.: what needs to be stacked on top of our base monad for the execution. In `Transport`, we then only need to pop the top of the stack, and voila. This greatly simplifies the implementation of the backends, as there's no longer any need to do any stack transformation: MySQL's implementation becomes a `runIdentityT`! This also removes most mentions of `TraceT` from the execution code since it's no longer required: we can rely on the base monad's existing `MonadTrace` constraint.
To continue encapsulating monadic actions in `DBStepInfo` and avoid threading a bunch of `forall` all over the place, this PR introduces a small local helper: `OnBaseMonad`. One only downside of all this is that this requires adding `MonadBaseControl IO m` constraint all over the place: previously, we would run directly on `IO` and lift, and would therefore not need to bring that constraint all the way.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7789
GitOrigin-RevId: e9b2e431c5c47fa9851abf87545c0415ff6d1a12
This upgrades the version of Ormolu required by the HGE repository to v0.5.0.1, and reformats all code accordingly.
Ormolu v0.5 reformats code that uses infix operators. This is mostly useful, adding newlines and indentation to make it clear which operators are applied first, but in some cases, it's unpleasant. To make this easier on the eyes, I had to do the following:
* Add a few fixity declarations (search for `infix`)
* Add parentheses to make precedence clear, allowing Ormolu to keep everything on one line
* Rename `relevantEq` to `(==~)` in #6651 and set it to `infix 4`
* Add a few _.ormolu_ files (thanks to @hallettj for helping me get started), mostly for Autodocodec operators that don't have explicit fixity declarations
In general, I think these changes are quite reasonable. They mostly affect indentation.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6675
GitOrigin-RevId: cd47d87f1d089fb0bc9dcbbe7798dbceedcd7d83
This is a first step towards clarifying the role of `UnpreparedValue` as part of the IR. It certainly does not belong in the parser framework.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4588
GitOrigin-RevId: d1582a0b266729b79e00d31057178a4099168e6d
## Description
This PR removes `RQL.Types`, which was now only re-exporting a bunch of unrelated modules.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4363
GitOrigin-RevId: 894f29a19bff70b3dad8abc5d9858434d5065417
I discovered and removed instances of Boolean Blindness about whether json numbers should be stringified or not.
Although quite far-reaching, this is a completely mechanical change and should have no observable impact outside the server code.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3763
GitOrigin-RevId: c588891afd8a6923a135c736f6581a43a2eddbc7
This PR simplifies the types that represent a remote relationship in IR so that they can be reused in other parts (in remote schema types) which could have remote relationships.
The comments on the PR explain the main changes.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2979
GitOrigin-RevId: 559c51d9d6ae79e2183ce4347018741b9096ac74
This commit applies ormolu to the whole Haskell code base by running `make format`.
For in-flight branches, simply merging changes from `main` will result in merge conflicts.
To avoid this, update your branch using the following instructions. Replace `<format-commit>`
by the hash of *this* commit.
$ git checkout my-feature-branch
$ git merge <format-commit>^ # and resolve conflicts normally
$ make format
$ git commit -a -m "reformat with ormolu"
$ git merge -s ours post-ormolu
https://github.com/hasura/graphql-engine-mono/pull/2404
GitOrigin-RevId: 75049f5c12f430c615eafb4c6b8e83e371e01c8e
Blocked on https://github.com/hasura/graphql-engine-mono/pull/1640.
While fiddling with BigQuery I noticed a severe issue with offset/limit for array-aggregates. I've fixed it now.
The basic problem was that I was using a query like this:
```graphql
query MyQuery {
hasura_Artist(order_by: {artist_self_id: asc}) {
artist_self_id
albums_aggregate(order_by: {album_self_id: asc}, limit: 2) {
nodes {
album_self_id
}
aggregate {
count
}
}
}
}
```
Producing this SQL:
```sql
SELECT `t_Artist1`.`artist_self_id` AS `artist_self_id`,
STRUCT(IFNULL(`aa_albums1`.`nodes`, NULL) AS `nodes`, IFNULL(`aa_albums1`.`aggregate`, STRUCT(0 AS `count`)) AS `aggregate`) AS `albums_aggregate`
FROM `hasura`.`Artist` AS `t_Artist1`
LEFT OUTER JOIN (SELECT ARRAY_AGG(STRUCT(`t_Album1`.`album_self_id` AS `album_self_id`) ORDER BY (`t_Album1`.`album_self_id`) ASC) AS `nodes`,
STRUCT(COUNT(*) AS `count`) AS `aggregate`,
`t_Album1`.`artist_other_id` AS `artist_other_id`
FROM (SELECT *
FROM `hasura`.`Album` AS `t_Album1`
ORDER BY (`t_Album1`.`album_self_id`) ASC NULLS FIRST
-- PROBLEM HERE
LIMIT @param0) AS `t_Album1`
GROUP BY `t_Album1`.`artist_other_id`)
AS `aa_albums1`
ON (`aa_albums1`.`artist_other_id` = `t_Artist1`.`artist_self_id`)
ORDER BY (`t_Artist1`.`artist_self_id`) ASC NULLS FIRST
```
Note the `LIMIT @param0` -- that is incorrect because we want to limit
per artist. Instead, we want:
```sql
SELECT `t_Artist1`.`artist_self_id` AS `artist_self_id`,
STRUCT(IFNULL(`aa_albums1`.`nodes`, NULL) AS `nodes`, IFNULL(`aa_albums1`.`aggregate`, STRUCT(0 AS `count`)) AS `aggregate`) AS `albums_aggregate`
FROM `hasura`.`Artist` AS `t_Artist1`
LEFT OUTER JOIN (SELECT ARRAY_AGG(STRUCT(`t_Album1`.`album_self_id` AS `album_self_id`) ORDER BY (`t_Album1`.`album_self_id`) ASC) AS `nodes`,
STRUCT(COUNT(*) AS `count`) AS `aggregate`,
`t_Album1`.`artist_other_id` AS `artist_other_id`
FROM (SELECT *,
-- ADDED
ROW_NUMBER() OVER(PARTITION BY artist_other_id) artist_album_index
FROM `hasura`.`Album` AS `t_Album1`
ORDER BY (`t_Album1`.`album_self_id`) ASC NULLS FIRST
) AS `t_Album1`
-- CHANGED
WHERE artist_album_index <= @param
GROUP BY `t_Album1`.`artist_other_id`)
AS `aa_albums1`
ON (`aa_albums1`.`artist_other_id` = `t_Artist1`.`artist_self_id`)
ORDER BY (`t_Artist1`.`artist_self_id`) ASC NULLS FIRST
```
That serves both the LIMIT/OFFSET function in the where clause. Then,
both the ARRAY_AGG and the COUNT are correct per artist.
I've updated my Haskell test suite to add regression tests for this. I'll push a commit for Python tests shortly. The tests still pass there.
This just fixes a case that we hadn't noticed.
https://github.com/hasura/graphql-engine-mono/pull/1641
GitOrigin-RevId: 49933fa5e09a9306c89565743ecccf2cb54eaa80
### Description
This PR adds the required IR for DB to DB joins, based on @paf31 and @0x777 's `feature/db-to-db` branch.
To do so, it also refactors the IR to introduce a new type parameter, `r`, which is used to recursively constructs the `v` parameter of remote QueryDBs. When collecting remote joins, we replace `r` with `Const Void`, indicating at the type level that there cannot be any leftover remote join.
Furthermore, this PR refactors IR.Select for readability, moves some code from IR.Root to IR.Select to avoid having to deal with circular dependencies, and makes it compile by adding `error` in all new cases in the execution pipeline.
The diff doesn't make it clear, but most of Select.hs is actually unchanged. Declarations have just been reordered by topic, in the following order:
- type declarations
- instance declarations
- type aliases
- constructor functions
- traverse functions
https://github.com/hasura/graphql-engine-mono/pull/1580
Co-authored-by: Phil Freeman <630306+paf31@users.noreply.github.com>
GitOrigin-RevId: bbdcb4119cec8bb3fc32f1294f91b8dea0728721
A pull request for cleaning up small issues, bugs, redundancies and missing things in the BigQuery backend.
Summary:
1. Remove duplicate projection fields - BigQuery rejects these.
2. Add order_by to the test suite cases, as it was returning inconsistent results.
3. Add lots of in FromIr about how the dataloader approach is given support.
4. Produce the correct output structure for aggregates:
a. Should be a singleton object for a top-level aggregate query.
b. Should have appropriate aggregate{} and nodes{} labels.
c. **Support for nodes** (via array_agg).
5. Smooth over support of array aggregates by removing the fields used for joining with an explicit projection of each wanted field.
https://github.com/hasura/graphql-engine-mono/pull/1317
Co-authored-by: Vamshi Surabhi <6562944+0x777@users.noreply.github.com>
GitOrigin-RevId: cd3899f4667770a27055f94988ef2a6d5808f1f5
Remote relationships are now supported on SQL Server and BigQuery. The major change though is the re-architecture of remote join execution logic. Prior to this PR, each backend is responsible for processing the remote relationships that are part of their AST.
This is not ideal as there is nothing specific about a remote join's execution that ties it to a backend. The only backend specific part is whether or not the specification of the remote relationship is valid (i.e, we'll need to validate whether the scalars are compatible).
The approach now changes to this:
1. Before delegating the AST to the backend, we traverse the AST, collect all the remote joins while modifying the AST to add necessary join fields where needed.
1. Once the remote joins are collected from the AST, the database call is made to fetch the response. The necessary data for the remote join(s) is collected from the database's response and one or more remote schema calls are constructed as necessary.
1. The remote schema calls are then executed and the data from the database and from the remote schemas is joined to produce the final response.
### Known issues
1. Ideally the traversal of the IR to collect remote joins should return an AST which does not include remote join fields. This operation can be type safe but isn't taken up as part of the PR.
1. There is a lot of code duplication between `Transport/HTTP.hs` and `Transport/Websocket.hs` which needs to be fixed ASAP. This too hasn't been taken up by this PR.
1. The type which represents the execution plan is only modified to handle our current remote joins and as such it will have to be changed to accommodate general remote joins.
1. Use of lenses would have reduced the boilerplate code to collect remote joins from the base AST.
1. The current remote join logic assumes that the join columns of a remote relationship appear with their names in the database response. This however is incorrect as they could be aliased. This can be taken up by anyone, I've left a comment in the code.
### Notes to the reviewers
I think it is best reviewed commit by commit.
1. The first one is very straight forward.
1. The second one refactors the remote join execution logic but other than moving things around, it doesn't change the user facing functionality. This moves Postgres specific parts to `Backends/Postgres` module from `Execute`. Some IR related code to `Hasura.RQL.IR` module. Simplifies various type class function signatures as a backend doesn't have to handle remote joins anymore
1. The third one fixes partial case matches that for some weird reason weren't shown as warnings before this refactor
1. The fourth one generalizes the validation logic of remote relationships and implements `scalarTypeGraphQLName` function on SQL Server and BigQuery which is used by the validation logic. This enables remote relationships on BigQuery and SQL Server.
https://github.com/hasura/graphql-engine-mono/pull/1497
GitOrigin-RevId: 77dd8eed326602b16e9a8496f52f46d22b795598
