无法连接PostgreSQL服务器，报错Connection refused如何解决？

Hey there, let's work through this connection issue you're hitting. The error message makes it clear your Django app can't reach the PostgreSQL server at 127.0.0.1:5432—here are the step-by-step fixes to get things working again:

1. Make sure the PostgreSQL service is running #

First things first: check if PostgreSQL is even up and running on your machine.

• On Windows, press Win + R, type services.msc, and hit Enter. Look for the PostgreSQL service (it'll have a name like postgresql-x64-<your-version>). If its status isn't "Running", right-click it and select Start.
• Alternatively, use Command Prompt: run net start postgresql-x64-14 (replace 14 with your PostgreSQL version number).

2. Verify PostgreSQL is listening on port 5432 #

Next, confirm the server is actually accepting connections on port 5432:

• Open Command Prompt and run:

  netstat -ano | findstr :5432
  

• If you see a line with LISTENING, the port is active. If not, we'll need to adjust PostgreSQL's config.

3. Update PostgreSQL's listening address #

If the port isn't listening, edit the postgresql.conf file to allow local connections:

• Find the file in C:\Program Files\PostgreSQL\<your-version>\data.
• Open it with a text editor, locate the listen_addresses line, and set it to:

  listen_addresses = '127.0.0.1'
  

  (You can also use '*' to allow connections from all addresses, but 127.0.0.1 is safer for local setups.)
• Save the file and restart the PostgreSQL service from the Services window.

4. Allow local connections in pg_hba.conf #

Even if the server is listening, PostgreSQL might block local connections. Check the pg_hba.conf file (also in the data directory):

• Add or ensure this line exists (adjust the authentication method if needed—scram-sha-256 is default for newer versions, md5 for older ones):

  host    all             all             127.0.0.1/32            scram-sha-256
  

• Save the file and restart PostgreSQL again.

5. Double-check Django's database configuration #

Make sure your Django settings match PostgreSQL's setup. Open your project's settings.py and verify the DATABASES section:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'your_database_name',  # Must match the DB you created in PostgreSQL
        'USER': 'your_postgres_username',  # Usually 'postgres' by default
        'PASSWORD': 'your_postgres_password',
        'HOST': '127.0.0.1',
        'PORT': '5432',
    }
}

Double-check that all values are correct—especially the database name and credentials.

6. Check Windows Firewall settings #

Sometimes the firewall blocks PostgreSQL's port. Try temporarily disabling Windows Firewall to test if that's the issue. If the connection works after disabling it:

• Go to Windows Defender Firewall > Advanced Settings > Inbound Rules.
• Create a new rule to allow traffic on port 5432, or allow the PostgreSQL executable (found in C:\Program Files\PostgreSQL\<version>\bin\postgres.exe).

If none of these steps work, check PostgreSQL's log files in C:\Program Files\PostgreSQL\<version>\data\pg_log—they'll have detailed error messages that can point to the root cause.

内容的提问来源于stack exchange，提问作者Lohith