@andrew_l/search-query-language

Search Query Language

Search Query Language is a lightweight utility that converts human-readable query strings into structured representations. It supports parsing expressions into an abstract syntax tree (AST) and transforming them into queries.

Documentation

✨ Features

• Expression Parsing: Convert query strings into an AST for structured processing.
• MongoDB Query Conversion: Transform expressions into MongoDB-compatible query objects.
• Flexible Syntax Support: Supports comparison operators like =, !=, >, <, >=, <=.

🔍 Search Syntax

The following table lists the syntax that you can use to construct a query.

Syntax	Usage	Description	Examples
=	field="value"	Exact match	name="andrew"
!=	field!="value"	Not equal to	status!="active"
<	field<value	Less than	amount<5000
<=	field<=value	Less than or equal to	amount<=10000
>	field>value	Greater than	created>1672531200
>=	field>=value	Greater than or equal to	created>=1672531200
AND	condition1 AND condition2	Combine conditions (both must be true)	status="active" AND age>=18
OR	condition1 OR condition2	Combine conditions (either can be true)	status="stop" OR age>40
()	(condition1 OR condition2) AND condition3	Group conditions to control logic precedence	(status="active" OR status="stop") AND age>18

📌 Notes

• The left operand must always be an identifier (e.g., a field name), while the right operand must always be a literal value (e.g., a string, number, or boolean).
• Support comparison operators (<, <=, >, >=).
• Use AND and OR to combine conditions.
• Parentheses () help group conditions for better control over query logic.

🚀 Example: Minimal

import { parseToMongo } from '@andrew_l/search-query-language';

const clients = db.collection('clients');

// GET /clients?search="age>18"
app.get('/clients', async (req, res) => {
  const filter = parseToMongo(req.query.search);
  const items = await clients.find(filter).toArray();
  res.json(items);
});

🚀 Example: Usage MongoDB

import { parseToMongo } from '@andrew_l/search-query-language';

// GET /clients?search="active=true AND age>18"
app.get('/clients', async (req, res) => {
  const filter = parseToMongo(req.query.search, {
    transform: {
      _id: [MONGO_TRANSFORM.OBJECT_ID, MONGO_TRANSFORM.NOT_NULLABLE],
    },
  });

  const items = await db.collection('clients').find(filter).toArray();

  res.json(items);
});

🚀 Example: Usage Mongoose

import mongoose from 'mongoose';
import { parseToMongoose } from '@andrew_l/search-query-language';

const Client = mongoose.Model('Clients', new mongoose.Schema({
  email: String;
  active: Boolean;
}))

// GET /clients?search="email="[e-mail]" AND active=true"
app.get('/clients', async (req, res) => {
  const filter = parseToMongoose(Client, req.query.search);
  const items = await Client.find(filter).lean();

  res.json(items);
});