Your first core query

Use @quory/core when you want the relationship engine in your own Node.js code. It does not require React or the desktop app.

Install core and a driver

npm install @quory/core @quory/postgres

For MySQL or SQLite, replace the driver package with @quory/mysql or @quory/sqlite. See database connections for their constructors and schema naming.

Keep database credentials and driver code on the server.

Connect and discover the schema

This example assumes a PostgreSQL database with public.customers(id, email) and public.orders(id, customer_id), with a foreign key from orders.customer_id to customers.id. Substitute tables and columns from your own database.

import { ConditionOperator, getSchemas, runQuery } from "@quory/core";
import { PostgresDriver } from "@quory/postgres";

const driver = new PostgresDriver({
  host: process.env.PGHOST ?? "localhost",
  port: Number(process.env.PGPORT ?? 5432),
  database: process.env.PGDATABASE,
  username: process.env.PGUSER,
  password: process.env.PGPASSWORD,
});

try {
  await driver.testConnection();
  const schemas = await getSchemas(driver);

  const result = await runQuery(driver, schemas, {
    base: {
      tableRef: "public.customers",
      select: ["id", "email"],
      where: {
        column: "email",
        operator: ConditionOperator.EQUALS,
        value: "alex@example.com",
      },
      joins: [{ tableRef: "public.orders", select: ["id"] }],
    },
    limit: 25,
    offset: 0,
  });

  for (const row of result.rows) {
    for (const record of row) {
      console.log(record.tableRef, record.data);
    }
  }
} finally {
  await driver.teardown();
}

getSchemas is asynchronous. Await it before planning or running a query. The joins array belongs inside base (and can be nested inside another join).

Read the result

runQuery returns sql, meta, and rows. Each result row contains an array of records, one for each prepared join. Each record identifies its table and join alias and puts the selected column values in data.

A customer with several orders can appear in several rows. An inner join excludes a customer with no orders. Use tableRef and joinAlias to distinguish records rather than relying on a hardcoded array position or generated SQL alias.

The one-shot example closes the driver in finally. In a service, keep the driver for the service lifetime and call teardown() during shutdown.

Next, learn to inspect your schema or filter and paginate queries.