Module graphql 

GraphQL-to-SQL Gateway

Feature 12 of the HeliosProxy roadmap.

This module provides a GraphQL gateway that automatically generates efficient SQL queries from GraphQL requests. It includes:

• Automatic schema introspection from database tables
• Efficient SQL generation with JOIN optimization
• N+1 query prevention via DataLoader pattern
• Query complexity analysis and limits
• Branch-aware and time-travel queries (HeliosDB-Lite integration)

Architecture

GraphQL Query → Parse → Validate → Plan → Generate SQL → Execute → Shape Response

Example

use heliosdb::proxy::graphql::{GraphQLEngine, GraphQLConfig};

let config = GraphQLConfig::builder()
    .endpoint("/graphql")
    .playground(true)
    .max_depth(10)
    .build();

let engine = GraphQLEngine::new(config, db_pool).await?;

let response = engine.execute(GraphQLRequest {
    query: "query { users { id name } }".to_string(),
    variables: None,
    operation_name: None,
}).await?;

Re-exports

pub use config::GraphQLConfig;

pub use config::GraphQLConfigBuilder;

pub use config::TableConfig;

pub use config::RelationshipConfig;

pub use engine::GraphQLEngine;

pub use engine::GraphQLRequest;

pub use engine::GraphQLResponse;

pub use engine::GraphQLError;

pub use introspector::SchemaIntrospector;

pub use introspector::GraphQLSchema;

pub use introspector::GraphQLType;

pub use introspector::GraphQLField;

pub use sql_generator::SqlGenerator;

pub use sql_generator::SqlQuery;

pub use sql_generator::QueryPlan;

pub use sql_generator::Selection;

pub use sql_generator::Filter;

pub use dataloader::DataLoader;

pub use dataloader::DataLoaderConfig;

pub use dataloader::BatchResult;

pub use resolver::FieldResolver;

pub use resolver::ResolverContext;

pub use resolver::ResolverResult;

pub use validation::QueryValidator;

pub use validation::ValidationError;

pub use validation::ComplexityResult;

pub use metrics::GraphQLMetrics;

pub use metrics::QueryStats;

pub use metrics::OperationMetrics;

Modules

config

GraphQL Gateway Configuration

dataloader

DataLoader

engine

GraphQL Engine

introspector

Schema Introspector

metrics

GraphQL Metrics

resolver

Field Resolver

sql_generator

SQL Generator

validation

Query Validation

Structs

BranchContext

Branch context for HeliosDB branch-aware queries

ExecutionContext

GraphQL execution context

Enums

ConsistencyLevel

Consistency level for GraphQL queries (HeliosDB integration)

DistanceMetric

Distance metric for vector searches

ErrorCode

GraphQL error codes

GraphQLScalar

GraphQL scalar types mapped from SQL

OperationType

GraphQL operation type

RelationType

Relationship type between tables

Functions

to_camel_case

Convert string to camelCase

to_pascal_case

Convert string to PascalCase

to_snake_case

Convert string to snake_case