Struct QueryCorrelator 

pub struct QueryCorrelator {
    pub left_prefix: Option<String>,
    pub right_prefix: Option<String>,
}

Query result correlator for joining data from multiple databases

Enables joining and correlating query results from different databases using common keys, similar to SQL JOINs but across distributed databases.

Example

use rust_logic_graph::multi_db::{QueryCorrelator, JoinStrategy};
use serde_json::json;
 
let mut correlator = QueryCorrelator::new();
 
// Data from OMS database
let users = json!([
    {"user_id": 1, "name": "Alice"},
    {"user_id": 2, "name": "Bob"},
]);
 
// Data from Orders database
let orders = json!([
    {"order_id": 101, "user_id": 1, "amount": 50.0},
    {"order_id": 102, "user_id": 1, "amount": 75.0},
    {"order_id": 103, "user_id": 3, "amount": 100.0},
]);
 
let result = correlator.join(
    &users,
    &orders,
    "user_id",
    "user_id",
    JoinStrategy::Inner
).unwrap();
 
println!("Joined {} rows", result.as_array().unwrap().len());

Fields

left_prefix: Option<String>

Optional prefix for disambiguating column names from left dataset

right_prefix: Option<String>

Optional prefix for disambiguating column names from right dataset

Implementations

impl QueryCorrelator

pub fn new() -> Self

Create a new query correlator

pub fn with_left_prefix(self, prefix: impl Into<String>) -> Self

Set prefix for left dataset columns (e.g., “user_”)

pub fn with_right_prefix(self, prefix: impl Into<String>) -> Self

Set prefix for right dataset columns (e.g., “order_”)

pub fn join( &self, left: &Value, right: &Value, left_key: &str, right_key: &str, strategy: JoinStrategy, ) -> Result<Value, RustLogicGraphError>

Join two datasets on specified keys

Arguments

• left - Left dataset (JSON array of objects)
• right - Right dataset (JSON array of objects)
• left_key - Key field name in left dataset
• right_key - Key field name in right dataset
• strategy - Join strategy (Inner, Left, Right, Full)

Returns

JSON array containing joined rows

Trait Implementations

impl Default for QueryCorrelator

fn default() -> Self

Returns the “default value” for a type.