Struct QueryEngine 

pub struct QueryEngine { /* private fields */ }

Query engine for executing SQL against a projection store.

The engine is stateless and can be shared across threads. It holds only the schema definition.

Implementations

impl QueryEngine

pub fn new(schema: Schema) -> Self

Creates a new query engine with the given schema.

pub fn schema(&self) -> &Schema

Returns a reference to the schema.

pub fn query<S: ProjectionStore>( &self, store: &mut S, sql: &str, params: &[Value], ) -> Result<QueryResult>

Executes a SQL query against the current store state.

Arguments

• store - The projection store to query
• sql - SQL query string
• params - Query parameters (for $1, $2, etc.)

Example

let result = engine.query(
    &mut store,
    "SELECT name FROM users WHERE id = $1",
    &[Value::BigInt(42)],
)?;

pub fn query_at<S: ProjectionStore>( &self, store: &mut S, sql: &str, params: &[Value], position: Offset, ) -> Result<QueryResult>

Executes a SQL query at a specific log position (point-in-time query).

This enables compliance queries that show the state as it was at a specific point in the log.

Arguments

• store - The projection store to query
• sql - SQL query string
• params - Query parameters
• position - Log position to query at

Example

// Get user state as of log position 1000
let result = engine.query_at(
    &mut store,
    "SELECT * FROM users WHERE id = 1",
    &[],
    Offset::new(1000),
)?;

pub fn prepare(&self, sql: &str, params: &[Value]) -> Result<PreparedQuery>

Parses a SQL query without executing it.

Useful for validation or query plan inspection.

Trait Implementations

impl Clone for QueryEngine

fn clone(&self) -> QueryEngine

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QueryEngine

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.