Add Support for Vector Data Type in SQL for GraphQL

[RubenCerna2079]

Why make this change?

• Solves issue Add Vector Support for GraphQL #3682

What is this change?

• In order to allow graphql to read array types that are not [string] we moved the section that parses the scalar values to types hot chocolate can use in order output them to the user. This new CoerceJsonLeafValueToRuntimeType method is then used in a loop to allow support for arrays inside the ExecutionHelper.cs file.
• In multiple places throughout the code, DAB looks at the SyntaxKind of the values it is working with in order to know if the value can be directly used or if it has a relationship with another entity. In order to allow graphql to write to the data base, we now add a new function TryGetUnderlyingFieldKind in ISqlMetadataProvider.cs that checks if the value is a list and it comes from a row that has the IsArrayType. If that condition is met, then it means the list value we have should be processed as a regular ScalarType and not as a List/Object that is a relationship to a different entity. This method is used in the following files: MultipleMutationInputValidator.cs, MultipleCreateOrderHelper.cs, SqlMutationEnginge.cs.
• Lastly, as part to allow graphql to write to the data base, we add a new GetStringifiedValue function that checks if the value that we are going to parse to the data base is a list or a regular value and transforms it into a string accordingly. Since we set all values as strings, this is something that cannot be directly done with a list as the .ToString() function will return a useless value. This value is then parsed before being used as a parameter in the data base query.

How was this tested?

• Integration Tests
• Unit Tests
  Added tests that query (read) from the data base as well as mutation (change) to the data base such as create, update, and delete.

Sample Request(s)

Query

query {
  dbo_normalvectors {
    items {
      Embedding
      ProductID
    }
  }
}

Create

mutation {
  createdbo_normalvector(
    item: { ProductID: 10000, Embedding: [125, 1.22222, 0.75] }
  ) {
    ProductID
    Embedding
  }
}

Update

mutation {
  updatedbo_normalvector(
    ProductID: 10000,
    item: { Embedding: [0.532, 200, 100.152] }
  ) {
    ProductID
    Embedding
  }
}

Delete

mutation {
  deletedbo_normalvector(
    ProductID: 10000
  ) {
    ProductID
    Embedding
  }
}

[Copilot]

Pull request overview

This PR adds end-to-end GraphQL support for SQL Server vector/array-backed columns by (1) coercing leaf-list results into HotChocolate runtime scalar types, and (2) ensuring list-valued mutation inputs for array columns are treated as scalars (not relationships) and correctly parameterized for SQL.

Changes:

• Add leaf-list result coercion (CoerceJsonLeafValueToRuntimeType) so GraphQL can return list-of-scalar fields (e.g., vector exposed as [Single]) without HotChocolate leaf coercion errors.
• Add ISqlMetadataProvider.TryGetUnderlyingFieldKind and plumb it through mutation validation/parsing so array columns aren’t misclassified as relationship inputs.
• Add MSSQL integration tests + enable GraphQL for the VectorType test entity, plus stringify list inputs for SQL parameters.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/Service.Tests/SqlTests/GraphQLQueryTests/MsSqlGraphQLVectorTypesTests.cs	Adds GraphQL integration coverage for vector read/query + create/update/delete mutations.
src/Service.Tests/dab-config.MsSql.json	Enables GraphQL for the VectorType entity in MSSQL test config.
src/Core/Services/TypeHelper.cs	Adds SystemType→SyntaxKind mapping helper used for array column kind detection.
src/Core/Services/MultipleMutationInputValidator.cs	Uses underlying kind detection to avoid treating array scalar lists as relationship fields.
src/Core/Services/MetadataProviders/SqlMetadataProvider.cs	Implements TryGetUnderlyingFieldKind for SQL-backed metadata providers.
src/Core/Services/MetadataProviders/ISqlMetadataProvider.cs	Adds the TryGetUnderlyingFieldKind API to the provider contract.
src/Core/Services/MetadataProviders/CosmosSqlMetadataProvider.cs	Implements the new API as “not supported” for Cosmos.
src/Core/Services/ExecutionHelper.cs	Refactors scalar coercion and adds list-of-leaf coercion to runtime types for HotChocolate.
src/Core/Resolvers/SqlMutationEngine.cs	Plumbs metadata provider into mutation input parsing to distinguish array columns from relationships.
src/Core/Resolvers/Sql Query Structures/SqlUpdateQueryStructure.cs	Uses GetStringifiedValue so list values are correctly converted before parameter parsing.
src/Core/Resolvers/Sql Query Structures/SqlInsertQueryStructure.cs	Uses GetStringifiedValue for insert parameter values.
src/Core/Resolvers/Sql Query Structures/BaseSqlQueryStructure.cs	Adds GetStringifiedValue to serialize list inputs into JSON array strings for parsing.
src/Core/Resolvers/MultipleCreateOrderHelper.cs	Uses underlying kind detection to treat array scalar lists as scalars.
config-generators/mssql-commands.txt	Updates generator command to enable GraphQL for VectorType.