query-builder

The DBCube Query Builder is a lightweight, flexible, and fluent library for building queries across multiple database engines, including MySQL, PostgreSQL, SQLite, and MongoDB, using JavaScript/Node.js.

Its agnostic design allows you to generate data manipulation (DML) and data definition (DDL) operations with a clean, chainable syntax—without sacrificing power or expressiveness.

It’s designed to work seamlessly in both SQL and NoSQL environments, providing a consistent abstraction layer across different storage technologies while still leveraging the native capabilities of each engine.

Features

• Fluent API for building SQL queries
• Type-safe query construction
• Support for SELECT, INSERT, UPDATE, DELETE
• Advanced WHERE conditions (AND, OR, groups, BETWEEN, IN, NULL checks)
• JOINs: INNER, LEFT, RIGHT
• Aggregations: COUNT, SUM, AVG, MAX, MIN
• Ordering, Grouping, Distinct, Pagination
• Column management (future extension)
• Promise-based asynchronous API
• Singleton connection management

Installation

npm install @dbcube/query-builder

Quick Start

import Database from "@dbcube/query-builder";

const db = new Database("my_database");

// Select all users
const users = await db.table("users").get();

// Select users with conditions
const activeUsers = await db
  .table("users")
  .where("status", "=", "active")
  .orderBy("created_at", "DESC")
  .limit(10)
  .get();

// Insert new users
await db
  .table("users")
  .insert([{ name: "John", email: "john@example.com", age: 30 }]);

// Update a user
await db.table("users").where("id", "=", 1).update({ status: "inactive" });

// Delete users
await db.table("users").where("status", "=", "deleted").delete();

API Documentation

Database

new Database(name: string)

Creates a new database connection instance.

table(tableName: string): Table

Returns a Table instance for building queries on the specified table.

Table

Query Methods

• select(fields?: string[]): Specify columns to select.
• where(column, operator, value): Add a WHERE condition.
• orWhere(column, operator, value): Add an OR WHERE condition.
• whereGroup(callback): Grouped WHERE conditions.
• whereBetween(column, [min, max]): WHERE BETWEEN condition.
• whereIn(column, values): WHERE IN condition.
• whereNull(column): WHERE IS NULL condition.
• whereNotNull(column): WHERE IS NOT NULL condition.
• join(table, column1, operator, column2): INNER JOIN.
• leftJoin(table, column1, operator, column2): LEFT JOIN.
• rightJoin(table, column1, operator, column2): RIGHT JOIN.
• orderBy(column, direction): ORDER BY clause.
• groupBy(column): GROUP BY clause.
• distinct(): DISTINCT clause.
• count(column?): COUNT aggregation.
• sum(column): SUM aggregation.
• avg(column): AVG aggregation.
• max(column): MAX aggregation.
• min(column): MIN aggregation.
• limit(number): LIMIT clause.
• page(number): Pagination (requires limit).

Execution Methods

• get(): Execute and return all matching rows.
• first(): Execute and return the first matching row.
• find(value, column?): Find a row by column value (default: id).
• insert(data): Insert one or more rows.
• update(data): Update rows matching the conditions.
• delete(): Delete rows matching the conditions.

Example Usage

// Complex query with joins, grouping, and aggregation
const results = await db
  .table("orders")
  .join("users", "orders.user_id", "=", "users.id")
  .where("orders.status", "=", "completed")
  .groupBy("users.country")
  .sum("orders.total")
  .orderBy("sum", "DESC")
  .limit(5)
  .get();

Error Handling

All methods throw descriptive errors for invalid usage, such as missing WHERE conditions on update/delete, or invalid data types.

License

This project is licensed under the MIT License.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

About

dbcube-query-builder is part of the dbcube ecosystem, designed to provide a robust and flexible query building experience for modern Node.js applications.