How to Fix DatabaseError in TypeScript When Deploying

Dealing with a DatabaseError in your TypeScript project? You're in the right place. Let's solve this step by step.

What Causes This Error

A DatabaseError when deploying typically means your application can't communicate with the database. Common causes include incorrect connection strings, connection pool exhaustion, missing migrations, or network issues between your app and the database server.

The Fix

The key is to configure connection pooling and timeouts in your TypeORM data source:

import { DataSource } from "typeorm";

export const AppDataSource = new DataSource({
  type: "postgres",
  url: process.env.DATABASE_URL,
  synchronize: false,
  logging: ["error", "warn"],
  extra: {
    max: 10,
    connectionTimeoutMillis: 5000,
  },
});

await AppDataSource.initialize();
console.log("Database connected");

Common Pitfall

If this error appears intermittently, it likely points to a race condition or resource exhaustion issue rather than a simple misconfiguration. Check your connection pool settings and timeouts. Adding a comment in your configuration explaining why this setting exists will save your future self — and teammates — hours of confusion.

Verify the Fix

After applying the fix, restart your TypeScript application and verify the error no longer appears in the console or logs. Test both the happy path and edge cases to be thorough. If the error persists, double-check that your changes were saved and the application fully restarted.

Prevention

Want to catch errors like this before they reach production? [Bugsly](https://bugsly.dev) provides real-time error tracking for TypeScript applications.