pool-mysql

library2.2.14jsnpmunverified

A MySQL connection pool wrapper with multiple pool support, async/await, connection tagging, and schema-based ORM-like query builder. Latest stable version is 2.2.14, released around 2022. It depends on the mysql package and provides features like writer/reader separation, model definitions with references (one-to-one, one-to-many), and populate queries. Key differentiators include environment-based configuration, priority/limit connection tagging, and a Schema class for defining columns with types like PK, FK, ENUM, Polygon, and DateTime. The library is TypeScript-typed and designed for Node.js, but its activity is low and may lack active maintenance.

database

npm install pool-mysql

package ↗

INSTALL

IMPORT

SIG · POOL-MYSQL

pool-mysql

databasejavascriptv2.2.14

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import pool from 'pool-mysql'

✗ const pool = require('pool-mysql')

The package exports a default object with query, createPool, connection, Schema etc. In TypeScript, default import works.

Schema

✓ import { Schema } from 'pool-mysql'

✗ import Schema from 'pool-mysql'

Schema is a named export, not default. Also accessible via pool.Schema.

pool.query

✓ pool.query(sql, values, callback)

✗ pool.query(sql, values)

The query method expects a callback; without it, the call will hang or error. Use pool.q for async/await.

pool.createPool

✓ pool.createPool(options)

✗ pool.createPool({ options })

Pass the options object directly, not wrapped in another object. The documentation shows `pool.createPool({ options })` but that's likely a typo; it should be `pool.createPool(options)`.

connection.q

✓ const result = await connection.q(sql, values)

✗ connection.q(sql, values)

q is async, so you must await it or use .then(). Without await, you get a Promise.

Shows three common usage patterns: callback query, async/await with connection.q, and custom pool creation.

import pool from 'pool-mysql'; // Environment config needed: SQL_HOST, SQL_USER, SQL_PASSWORD, SQL_TABLE etc. // Basic query with callback pool.query('SELECT * FROM users WHERE id = ?', [1], (err, data) => { if (err) throw err; console.log(data); }); // Async/await query async function main() { const connection = pool.connection(); try { const result = await connection.q('SELECT * FROM users LIMIT ?', [10]); console.log(result); } catch (err) { console.error(err); } finally { connection.release(); } } main(); // Custom pool const options = { writer: { host: process.env.SQL_HOST_READER || process.env.SQL_HOST }, reader: { host: process.env.SQL_HOST_READER || process.env.SQL_HOST }, forceWriter: false }; const pool2 = pool.createPool(options);

Debug

Known issues

gotchapool.query requires a callback; for async/await use pool.q or connection.q

fix

Use pool.q(sql, values) or connection.q(sql, values) with await

affects: >=1.0

gotchaEnvironment variables must be set (SQL_HOST, SQL_USER, SQL_PASSWORD, SQL_TABLE) or pool will fail

fix

Set required env vars or use dotenv package

affects: >=1.0

deprecatedThe mysql npm package is in maintenance mode; pool-mysql may have similar issues

fix

Consider using mysql2 or other actively maintained drivers

affects: >=1.0

gotchapool.createPool({ options }) in README is misleading; should be pool.createPool(options)

fix

Pass the options object directly, not wrapped in another object

affects: >=2.0

gotchaConnection tagging with limit: if limit is reached, pool will wait indefinitely

fix

Set a timeout or ensure connections are released promptly

affects: >=2.0

breakingNo default export for require in older versions? Check documentation as it may have changed

fix

Use `const pool = require('pool-mysql')` for CJS

affects: <=2.0

Errors

Common errors & fixes

TypeError: pool.query is not a function

Using import incorrectly: import pool from 'pool-mysql' returns an object with query, but if using require('pool-mysql') without default, it may be different.

fix

Ensure import style matches: const pool = require('pool-mysql') for CJS, or import pool from 'pool-mysql' for ESM

Error: Cannot find module 'mysql'

Missing peer dependency mysql

fix

npm install mysql --save

Error: SQL_HOST is not defined

Environment variables not set

fix

Set SQL_HOST, SQL_USER, SQL_PASSWORD, SQL_TABLE in environment or use dotenv

TypeError: pool.query(...) is not a function

Calling pool.query without callback? Actually pool.query is a function, but this error may arise if using pool.q incorrectly.

fix

Use pool.query(sql, values, callback) or pool.q(sql, values) for async

Upgrade

Version history

2.2.14latest on npm

Audit

Dependencies

mysqlrequiredCore dependency for MySQL driver

Agent activity

7 hits · last 30 days

node

Resources

packagepool-mysql ↗