Last updated: 2026-10-07

CHAIN YOUR MYSQL QUERIES ACROSS READ AND WRITE POOLS!

A Node.js MySQL connection pool with read-write splitting, a chainable query builder, and slow query logging

• Features
• Architecture
• License
• Author

npm install @pardnchiu/mysql-pool · Documentation

• Read-Write Split Pools — Maintains separate read and write connection pools, configured from an object or DB_READ_*/DB_WRITE_* environment variables, with the write side falling back to the read config when omitted.
• Chainable Query Builder — Chain select, where, join, orderBy, and limit from table() through get(), binding every value through placeholders instead of string concatenation.
• Pagination Total in One Query — total() attaches the full row count via the COUNT(*) OVER() window function, so paging never needs a second COUNT query.
• UPSERT with MySQL Function Allowlist — Values matching allowlisted functions such as NOW() and UUID() are inlined into SQL while everything else is bound as a parameter.
• Slow Query Logging and Graceful Shutdown — Logs the duration and SQL of any query over 20ms and releases both pools automatically on SIGINT/SIGTERM.

Full Architecture

graph TB
    App[Application] --> Init["init()"]
    Init --> Cfg[Config Resolution<br/>object / env vars]
    Cfg --> RP[(Read Pool)]
    Cfg --> WP[(Write Pool)]
    App --> QB[Chainable Query Builder]
    App --> Raw["read() / write()"]
    QB --> Exec["query() Executor<br/>slow query log"]
    Raw --> Exec
    Exec --> RP
    Exec --> WP

This project is licensed under the MIT LICENSE.

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©️ 2025 邱敬幃 Pardn Chiu