# @azmr/query

> Chainable, data-first query builder over arrays or reactive Signals.

Source: https://platform.azmara.io/docs/packages/query

## Installation

```bash
pnpm add @azmr/query @azmr/core
```

## Basic usage

```typescript
import { query } from "@azmr/query";

const customers = [
  { name: "Aroha", balance: 150 },
  { name: "Tane", balance: 0 },
  { name: "Mere", balance: 320 },
];

const result = query(customers)
  .where(c => c.balance > 0)
  .orderBy((a, b) => b.balance - a.balance)
  .limit(10)
  .select();
// → [{ name: "Mere", balance: 320 }, { name: "Aroha", balance: 150 }]
```

## With a reactive Signal

```typescript
import { Signal } from "@azmr/core";
import { query } from "@azmr/query";

const data = new Signal(customers);

const active = query(data)
  .where(c => c.balance > 0)
  .select();
```

## API Reference

| Method         | Description                                |
| -------------- | ------------------------------------------ |
| `.where(fn)`   | Filter rows — predicate must be a function |
| `.orderBy(fn)` | Sort with a comparator `(a, b) => number`  |
| `.limit(n)`    | Return at most `n` rows                    |
| `.offset(n)`   | Skip first `n` rows                        |
| `.select()`    | Execute and return results array           |
| `.count()`     | Return count of matching rows              |
| `.first()`     | Return first match or `undefined`          |

## Security

All predicates must be TypeScript functions — string-based queries throw a `TypeError`. This prevents eval injection at the type and runtime level.

```typescript
// ✅ Safe — TypeScript function
query(data).where(c => c.balance > 0)

// ❌ Throws TypeError — string predicates rejected
query(data).where("balance > 0" as any)
```