Connect from TypeORM to Neon

TypeORM is an open-source ORM that lets you to manage and interact with your database. This guide covers the following topics:

• Connect to Neon from TypeORM
• Use connection pooling with TypeORM
• Connection timeouts

Connect to Neon from TypeORM

To establish a basic connection from TypeORM to Neon, perform the following steps:

1. Retrieve your Neon connection string. In the Connection Details widget on the Neon Dashboard, select a branch, a user, and the database you want to connect to. A connection string is constructed for you. The connection string includes the user name, password, hostname, and database name.

2. Update the TypeORM's DataSource initialization in your application to the following:

   import { DataSource } from 'typeorm';
   
   export const AppDataSource = new DataSource({
     type: 'postgres',
     url: process.env.DATABASE_URL,
     ssl: true,
     entities: [
       /*list of entities*/
     ],
   });

3. Add a DATABASE_URL variable to your .env file and set it to the Neon connection string that you copied in the previous step. We also recommend adding ?sslmode=require to the end of the connection string to ensure a secure connection.

   Your setting will appear similar to the following:

   DATABASE_URL="postgresql://[user]:[password]@[neon_hostname]/[dbname]?sslmode=require"

Use connection pooling with TypeORM

Serverless functions can require a large number of database connections as demand increases. If you use serverless functions in your application, we recommend that you use a pooled Neon connection string, as shown:

# Pooled Neon connection string
DATABASE_URL="postgresql://alex:AbC123dEf@ep-cool-darkness-123456-pooler.us-east-2.aws.neon.tech/dbname?sslmode=require"

A pooled Neon connection string adds -pooler to the endpoint ID, which tells Neon to use a pooled connection. You can add -pooler to your connection string manually or copy a pooled connection string from the Connection Details widget on the Neon Dashboard. Use the Pooled connection checkbox to add the -pooler suffix.

Connection timeouts

A connection timeout that occurs when connecting from TypeORM to Neon causes an error similar to the following:

Error: P1001: Can't reach database server at `ep-white-thunder-826300.us-east-2.aws.neon.tech`:`5432`
Please make sure your database server is running at `ep-white-thunder-826300.us-east-2.aws.neon.tech`:`5432`.

This error most likely means that the TypeORM query timed out before the Neon compute was activated.

A Neon compute has two main states: Active and Idle. Active means that the compute is currently running. If there is no query activity for 5 minutes, Neon places a compute into an idle state by default.

When you connect to an idle compute from TypeORM, Neon automatically activates it. Activation typically happens within a few seconds but added latency can result in a connection timeout. To address this issue, you can adjust your Neon connection string by adding a connect_timeout parameter. This parameter defines the maximum number of seconds to wait for a new connection to be opened. The default value is 5 seconds. A higher setting may provide the time required to avoid connection timeouts. For example:

DATABASE_URL="postgresql://[user]:[password]@[neon_hostname]/[dbname]?sslmode=require&connect_timeout=10"