Commit Graph

63 Commits

Author SHA1 Message Date
Antoine Leblanc
dec8579db8 Allow backend execution to happen on the base app monad.
### 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
2023-02-09 14:40:04 +00:00
Rakesh Emmadi
f2a5d7cef3 server/pro/multitenant: Postgres connection routing using kriti templates
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6822
Co-authored-by: paritosh-08 <85472423+paritosh-08@users.noreply.github.com>
Co-authored-by: Naveen Naidu <30195193+Naveenaidu@users.noreply.github.com>
Co-authored-by: Sooraj <8408875+soorajshankar@users.noreply.github.com>
Co-authored-by: Varun Choudhary <68095256+Varun-Choudhary@users.noreply.github.com>
Co-authored-by: Sean Park-Ross <94021366+seanparkross@users.noreply.github.com>
GitOrigin-RevId: 61cfc00a97de88df1ede3f26829a0d78ec9c0bc5
2023-01-25 07:14:31 +00:00
Daniel Chambers
bfdeaf0334 Data Connectors insert mutations support [GDC-609]
[GDC-609]: https://hasurahq.atlassian.net/browse/GDC-609?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7513
GitOrigin-RevId: cb401e3ed84c5b60ec59b63dc478a1162b360135
2023-01-17 00:35:22 +00:00
Abby Sassel
62eafe26b6 server: replace note about ignored _stringifyNumbers in MSSQL remote relationships plan
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7463
GitOrigin-RevId: d6be472f13cd30da3a5f0ace05190698c94e3347
2023-01-09 10:52:18 +00:00
Rakesh Emmadi
e1bf220b37 fix the issue with multiplexed queries, where a run-time exception caused by one subscription causes all subscriptions to fail (fix #9281)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7230
GitOrigin-RevId: e94764a4652e7ee99e0e39d64436aa05620086cb
2022-12-22 17:09:30 +00:00
Abby Sassel
a8500b44ed server/fix: stringify-numeric-types option in remote database relationships (fix #8387)
Fix bug where `stringify-numeric-types` option is not respected in remote database relationships

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7302
GitOrigin-RevId: a649b00b45ca0f67dc84ad893d3d98529b064c77
2022-12-19 14:04:58 +00:00
Samir Talwar
342391f39d Upgrade Ormolu to v0.5.
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
2022-11-02 20:55:13 +00:00
Auke Booij
05b3a64e8f Clean up Hasura.Prelude a bit
- Remove `onJust` in favor of the more general `for_`
- Remove `withJust` which was used only once
- Remove `hashNub` in favor of `Ord`-based `uniques`
- Simplify some of the implementations in `Hasura.Prelude`
- Add `hlint` hint from `maybe True` to `all`, and `maybe False` to `any`

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6173
GitOrigin-RevId: 2c6ebbe2d04f60071d2a53a2d43c6d62dbc4b84e
2022-10-03 21:50:53 +00:00
Lyndon Maydwell
2107c70e17 Kriti Transform of the DataConnectors Configuration [GDW-144]
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4996
GitOrigin-RevId: 26d367ab83df4b161f58133afab2788c6f0c9746
2022-07-19 01:52:50 +00:00
Tom Harding
2e7e6fd98a Move SchemaOptions to its own module, remove magic bools
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5048
GitOrigin-RevId: f666a10c6af5feda9d761d3ffee5c77695361fdf
2022-07-14 17:59:01 +00:00
Auke Booij
13fc1c62d1 Move Hasura.GraphQL.Parser.Column to .RQL.IR. and .GraphQL.Schema.
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
2022-05-30 22:07:57 +00:00
Naveen Naidu
1d641aa2ff server: support query tags for MSSQL data sources
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4373
GitOrigin-RevId: 45717defdc973f3b7f1c9b972e2d3c836eec4476
2022-04-28 19:34:45 +00:00
Antoine Leblanc
3cbcbd9291 Remove RQL/Types.hs
## 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
2022-04-27 13:58:47 +00:00
Karthikeyan Chinnakonda
2325755954 server: streaming subscriptions schema generation and tests (incremental PR - 3)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4259
Co-authored-by: Rikin Kachhia <54616969+rikinsk@users.noreply.github.com>
Co-authored-by: Brandon Simmons <210815+jberryman@users.noreply.github.com>
Co-authored-by: paritosh-08 <85472423+paritosh-08@users.noreply.github.com>
GitOrigin-RevId: 4d1b4ec3c01f3a839f4392d3b77950fc3ab30236
2022-04-22 19:54:11 +00:00
Karthikeyan Chinnakonda
362aca9db3 server: streaming subscriptions execution (Incremental PR - 2)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4016
GitOrigin-RevId: 778300dd5ea094bc76b8f96c046313132863f832
2022-04-07 14:43:01 +00:00
Evie Ciobanu
42480ee902 server: X -> MSSQL remote joins
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4097
GitOrigin-RevId: f39b82bac26f6ade83bd4f5e996dc26f5e048365
2022-04-06 07:20:10 +00:00
Philip Lykke Carlsen
23520f67d0 (Fix #8267) Handle subscriptions in MSSQL when results exceed 2048 characters
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3959
GitOrigin-RevId: ea037c9dc4392d1b98ee086f6c87f79ce8ea5c8f
2022-03-21 12:16:14 +00:00
Karthikeyan Chinnakonda
a13ed140e8 server: refactor the term "live query" to "subscription"
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4001
GitOrigin-RevId: 78a7ff5c88ac3751baa5e2b3ac6ee73b94c50051
2022-03-21 10:40:49 +00:00
Philip Lykke Carlsen
4ccc830bb8 Tidy up MSSQL.FromIr
## Description

We go through the module `Hasura.Backends.MSSQL.FromIr` and split it into separate self-contained units, which we document.

Note that this PR has a slightly opinionated follow-up PR #3909 .

### Related Issues

Fix #3666

### Solution and Design

The module `FromIr` has given rise to:

* `FromIr.Expression`
* `FromIr.Query`
* `FromIr.Delete`
* `FromIr.Insert`
* `FromIr.Update`
* `FromIr.SelectIntoTempTable`

And `Execute.MutationResponse` has become `FromIr.MutationResponse` (after some slight adaptation of types).

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3908
GitOrigin-RevId: 364acf1bcdf74f2e19464c31cdded12bd8e9aa59
2022-03-10 10:34:52 +00:00
Philip Lykke Carlsen
b9ad721ea6 Reduce boolean blindness by promoting data type StringifyNumbers
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
2022-02-23 20:19:24 +00:00
Rakesh Emmadi
793aede022 server/mssql: improve database exception handling and better API errors
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3487
GitOrigin-RevId: d3f696072e8290b45c2f81509ce31cb5c13a4aef
2022-02-07 14:12:55 +00:00
Rakesh Emmadi
08f1725698 server/mssql: expand transactions to GraphQL queries and mssql_run_sql API
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3286
GitOrigin-RevId: 0b37767e271dfa43d36fa7f7cc9928ba6a22964d
2022-01-14 14:09:22 +00:00
Evie Ciobanu
463a303390 server: add MSSQL module haddocks
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3293
GitOrigin-RevId: 3062d5b1f41ce1fb18afc78773a2c947d8765309
2022-01-10 22:55:48 +00:00
Gil Mizrahi
59ab1bbe57 refactor Hasura.Backends.MSSQL.Instances.Execute
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3265
GitOrigin-RevId: f7faa22be30ecc5a876dc40ad93cb8d2452de65e
2022-01-06 09:49:58 +00:00
Philip Lykke Carlsen
304ec36c3a (Fix #3154) Remove occurrences of Text in MSSQL IR in favor of dedicated data types.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3264
GitOrigin-RevId: 923ea2794bef9850f1aa5714b610890d02165882
2022-01-05 11:10:39 +00:00
Naveen Naidu
3a8fadb22b server/mssql: support read replicas
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2578
Co-authored-by: Rikin Kachhia <54616969+rikinsk@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
GitOrigin-RevId: 88a02f8a617006853b350f48f4317c78ab97435b
2022-01-04 11:54:56 +00:00
Gil Mizrahi
f919c27ba4 Add docstrings to the module headers of a few selected mssql modules
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3241
GitOrigin-RevId: 582a2e77c8120ad2dc818d5f0b51cf56afc79bc5
2022-01-03 17:17:18 +00:00
Gil Mizrahi
a5f2161e1c server/mssql: upsert - sql generation and execution
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3207
Co-authored-by: Rakesh Emmadi <12475069+rakeshkky@users.noreply.github.com>
GitOrigin-RevId: 92a4aa3cf802bc76858c4be4273a2f6a7d4aa395
2021-12-31 10:56:58 +00:00
Rakesh Emmadi
60183df1ea server/mssql: use temporary tables for insert mutation execution
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3205
GitOrigin-RevId: ff889ce43ed613c283edefa68992eab7c36db18c
2021-12-22 11:05:29 +00:00
Philip Lykke Carlsen
37ecb0e3b2 server/mssql: Generate upsert mutation schema
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3056
GitOrigin-RevId: 8d58ae983c4d3ad55dfeff744c891d77c7c6de1a
2021-12-15 17:08:26 +00:00
Rakesh Emmadi
f00404e0f6 server/mssql: update mutation, SQL generation and execution
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3059
GitOrigin-RevId: 4ed0cbf54ac2a7103cb2b7adc97b2dfdf9994c4f
2021-12-15 13:56:34 +00:00
Chris Parks
038a6113c3 Remove Identifier associated type family from Backend class (close #1758)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3096
GitOrigin-RevId: 03f218a76c5f333a77646a60c8c69767e2286ea6
2021-12-13 16:49:09 +00:00
Philip Lykke Carlsen
2fbcd783e7 Refactor XOnConflict and ExtraInsertData
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3055
GitOrigin-RevId: 06f7f92f0e09695f5f7bc02df457d3b96ac9f5f6
2021-12-09 09:06:56 +00:00
Vamshi Surabhi
23e1cb218a simplification of generalized joins execution
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
2021-12-07 13:12:57 +00:00
Philip Lykke Carlsen
4f6831d76e Defining the MSSQL update schema using said components
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2923
GitOrigin-RevId: 732988f666f00b3c5eebf6089f9887ee5d679c11
2021-11-26 13:48:09 +00:00
Rakesh Emmadi
4f32324759 server/mssql: refine and generalize mssql OUTPUT clause and temporary table syntax AST
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2931
GitOrigin-RevId: e6aef494a096ca119597dc92bcaf9f16e644a72a
2021-11-22 09:12:45 +00:00
Gil Mizrahi
0e65932355 server/mssql support delete mutations (close hasura/graphql-engine#7626)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2691
Co-authored-by: Abby Sassel <3883855+sassela@users.noreply.github.com>
Co-authored-by: Rakesh Emmadi <12475069+rakeshkky@users.noreply.github.com>
GitOrigin-RevId: 8b66cc30e8e036ee56a5267c1d2f308155951ae9
2021-11-19 17:06:01 +00:00
Philip Lykke Carlsen
84027dad04 Breaking up the Postgres implementation of the update-schema into reusable components
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2889
GitOrigin-RevId: 49c5d59a6f817832f11b1773b078aa24cc650ab5
2021-11-18 18:03:57 +00:00
David Overton
aac64f2c81 Source typename customization (close graphql-engine#6974)
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/1616
GitOrigin-RevId: f7eefd2367929209aa77895ea585e96a99a78d47
2021-10-29 14:43:14 +00:00
Rakesh Emmadi
8e88e73a52 server/mssql: add cascade to mssql_run_sql
<!-- Thank you for ss in the Title above ^ -->

## Description
<!-- Please fill thier. -->
<!-- Describe the changes from a user's perspective -->
We don't have dependency reporting mechanism for `mssql_run_sql` API i.e when a database object (table, column etc.) is dropped through the API we should raise an exception if any dependencies (relationships, permissions etc.) with the database object exists in the metadata.

This PR addresses the above mentioned problem by
-> Integrating transaction to the API to rollback the SQL query execution if dependencies exists and exception is thrown
-> Accepting `cascade` optional field in the API payload to drop the dependencies, if any
-> Accepting `check_metadata_consistency` optional field to bypass (if value set to `false`) the dependency check

### Related Issues
<!-- Please make surt title -->
<!-- Add the issue number below (e.g. #234) -->
Close #1853

### Solution and Design
<!-- How is this iss -->
<!-- It's better if we elaborate -->
The design/solution follows the `run_sql` API implementation for Postgres backend.

### Steps to test and verify
<!-- If this is a fehis is a bug-fix, how do we verify the fix? -->
- Create author - article tables and track them
- Defined object and array relationships
- Try to drop the article table without cascade or cascade set to `false`
- The server should raise the relationship dependency exists exception

## Changelog

-  `CHANGELOG.md` is updated with user-facing content relevant to this PR.
  If no changelog is required, then add the `no-changelog-required` label.

## Affected components
<!-- Remove non-affected components from the list -->

-  Server
-  Console
-  CLI
-  Docs
-  Community Content
-  Build System
-  Tests
-  Other (list it)

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2636
GitOrigin-RevId: 0ab152295394056c4ca6f02923142a1658ad25dc
2021-10-22 14:50:13 +00:00
Rakesh Emmadi
09ae6af337 server/mssql: insert SQL generation and execution
>

### Description
>
Insert mutations for MSSQL backend. This PR implements execution logic.

### Changelog

- [x] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server
- [x] Tests

### Related Issues
->
Close https://github.com/hasura/graphql-engine-mono/issues/2114

### Steps to test and verify
>
Track a MSSQL table and perform the generated insert mutation to test.

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2248
Co-authored-by: Abby Sassel <3883855+sassela@users.noreply.github.com>
Co-authored-by: Philip Lykke Carlsen <358550+plcplc@users.noreply.github.com>
GitOrigin-RevId: 936f138c80d7a928180e6e7b0c4da64ecc1f7ebc
2021-10-01 12:53:15 +00:00
Robert
11a454c2d6 server, pro: actually reformat the code-base using ormolu
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
2021-09-23 22:57:37 +00:00
Naveen Naidu
3d95c67748 server/query-tags: implement new metadata specification and API
https://github.com/hasura/graphql-engine-mono/pull/2203

GitOrigin-RevId: 6169fcce0c6dccaec055bf8e723e9aa7c19a7f0c
2021-09-23 12:38:56 +00:00
jkachmar
112d206fa6 Adds Remote Source Join Execution
https://github.com/hasura/graphql-engine-mono/pull/2038

Co-authored-by: Phil Freeman <630306+paf31@users.noreply.github.com>
GitOrigin-RevId: 0843bd0610822469f727d768810694b748fec790
2021-09-22 10:44:01 +00:00
Rakesh Emmadi
7ca48decfb server/mssql: integrate insert mutation schema parser for MSSQL backend
>

### Description
>
This PR is an incremental work towards [enabling insert mutations on MSSQL](https://github.com/hasura/graphql-engine-mono/pull/1974). In this PR, we generate insert mutation schema parser for MSSQL backend.

### Changelog

- [ ] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.

### Affected components

- [x] Server

https://github.com/hasura/graphql-engine-mono/pull/2141

GitOrigin-RevId: 8595008dece35f7fded9c52e134de8b97b64f53f
2021-08-31 13:35:49 +00:00
Naveen Naidu
f49e13c890 server: SQL query tags for GQL operations (closes #400)
https://github.com/hasura/graphql-engine-mono/pull/1393

GitOrigin-RevId: f867c16d8281865dac38c91f7dfcbf5815de898c
2021-07-29 08:30:10 +00:00
Aniket Deshpande
66f09eeaab MSSQL nodes aggregates & inherited roles
https://github.com/hasura/graphql-engine-mono/pull/1293

Co-authored-by: Chris Done <11019+chrisdone@users.noreply.github.com>
Co-authored-by: Abby Sassel <3883855+sassela@users.noreply.github.com>
GitOrigin-RevId: 776402dbbaf3d8166a62b1aaaf6abc7e584b3eb2
2021-07-08 20:50:09 +00:00
Antoine Leblanc
8a77386fcf server: IR for DB-DB joins
### 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
2021-06-17 23:13:05 +00:00
Vamshi Surabhi
e8e4f30dd6 server: support remote relationships on SQL Server and BigQuery (#1497)
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
2021-06-11 03:27:39 +00:00
Philip Lykke Carlsen
79a80c3f0a MSSQL: Validate variables in subscriptions (close #1210)
GitOrigin-RevId: 5888621dfe44f5f710c2431515114ce0e8864e61
2021-06-08 03:51:15 +00:00