Build a TypeScript App with CockroachDB and TypeORM

This tutorial shows you how run a simple application built with TypeORM.

Step 1. Start CockroachDB

Choose whether to run a temporary local cluster or a free CockroachDB cluster on CockroachDB Serverless (beta). The instructions below will adjust accordingly.

Create a free cluster

  1. If you haven't already, sign up for a CockroachDB Cloud account.
  2. Log in to your CockroachDB Cloud account.
  3. On the Clusters page, click Create Cluster.
  4. On the Create your cluster page, select CockroachDB Serverless.

    Note:

    This cluster will be free forever.

  5. Click Create your free cluster.

Your cluster will be created in approximately 20-30 seconds.

Set up your cluster connection

Once your cluster is created, the Connect to cluster-name dialog displays. Use the information provided in the dialog to set up your cluster connection for the SQL user that was created by default:

  1. In your terminal, run the second command from the dialog to create a new certs directory on your local machine and download the CA certificate to that directory:

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    curl --create-dirs -o ~/.postgresql/root.crt -O https://cockroachlabs.cloud/clusters/<cluster-id>/cert
    

    Your cert file will be downloaded to ~/.postgres/root.crt.

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    curl --create-dirs -o ~/.postgresql/root.crt -O https://cockroachlabs.cloud/clusters/<cluster-id>/cert
    

    Your cert file will be downloaded to ~/.postgres/root.crt.

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    mkdir -p $env:appdata\.postgresql\; Invoke-WebRequest -Uri https://cockroachlabs.cloud/clusters/<cluster-id>/cert -OutFile $env:appdata\.postgresql\root.crt
    

    Your cert file will be downloaded to %APPDATA%/.postgres/root.crt.

  2. Copy the connection string provided, which will be used in the next steps (and to connect to your cluster in the future).

    Warning:

    This connection string contains your password, which will be provided only once. If you forget your password, you can reset it by going to the SQL Users page.

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    cockroach sql --url 'postgresql://<username>:<password>@<serverless-host>:26257/defaultdb?sslmode=verify-full&sslrootcert='$HOME'/.postgresql/root.crt&options=--cluster=<cluster-id>'
    

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    cockroach sql --url 'postgresql://<username>:<password>@<serverless-host>:26257/defaultdb?sslmode=verify-full&sslrootcert='$HOME'/.postgresql/root.crt&options=--cluster=<cluster-id>'
    
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    cockroach sql --url "postgresql://<username>:<password>@<serverless-host>:26257/defaultdb?sslmode=verify-full&sslrootcert=$env:appdata/.postgresql/root.crt&options=--cluster=<cluster-id>"
    

    Where:

    • <username> is the SQL user. By default, this is your CockroachDB Cloud account username.
    • <password> is the password for the SQL user. The password will be shown only once in the Connection info dialog after creating the cluster.
    • <serverless-host> is the hostname of the serverless cluster.
    • <cluster-name> is the short name of your cluster plus the tenant ID. For example, funny-skunk-3. The <cluster-name> is used to identify your tenant cluster on a multitenant host.

    You can find these settings in the Connection parameters tab of the Connection info dialog.

  1. If you haven't already, download the CockroachDB binary.
  2. Run the cockroach demo command:

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    $ cockroach demo \
    --no-example-database
    

    This starts a temporary, in-memory cluster and opens an interactive SQL shell to the cluster. Any changes to the database will not persist after the cluster is stopped.

    Note:

    If cockroach demo fails due to SSL authentication, make sure you have cleared any previously downloaded CA certificates from the directory ~/.postgresql.

  3. Take note of the (sql) connection string in the SQL shell welcome text:

    # Connection parameters:
    #   (webui)    http://127.0.0.1:8080/demologin?password=demo76950&username=demo
    #   (sql)      postgres://demo:demo76950@127.0.0.1:26257?sslmode=require
    #   (sql/unix) postgres://demo:demo76950@?host=%2Fvar%2Ffolders%2Fc8%2Fb_q93vjj0ybfz0fz0z8vy9zc0000gp%2FT%2Fdemo070856957&port=26257
    

Step 2. Create a database

  1. In the SQL shell, create the bank database that your application will use:

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    > CREATE DATABASE bank;
    
  2. Create a SQL user for your app:

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    > CREATE USER <username> WITH PASSWORD <password>;
    

    Take note of the username and password. You will use it in your application code later.

  3. Give the user the necessary permissions:

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    > GRANT ALL ON DATABASE bank TO <username>;
    
  1. If you haven't already, download the CockroachDB binary.
  2. Start the built-in SQL shell using the connection string you got from the CockroachDB Cloud Console earlier:

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    $ cockroach sql \
    --url='postgres://<username>:<password>@<global host>:26257/<cluster_name>.defaultdb?sslmode=verify-full&sslrootcert=<certs_dir>/cc-ca.crt'
    

    In the connection string copied from the CockroachDB Cloud Console, your username, password and cluster name are pre-populated. Replace the <certs_dir> placeholder with the path to the certs directory that you created earlier.

  3. In the SQL shell, create the bank database that your application will use:

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    > CREATE DATABASE bank;
    
  4. Exit the SQL shell:

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    > \q
    

Step 3. Get the code

Clone the code's GitHub repository.

Step 4. Update the connection parameters

Open the ormconfig.ts file, and edit the ORM configuration parameters:

  • Replace the value for port with the port to your cluster.
  • Replace the value for username with the user you created earlier.
  • Replace the value for password with the password you created for your user.
  • At the top of the file, uncomment the import * as fs from "fs"; line.

    This line imports the fs Node module, which enables you to read in the CA cert that you downloaded from the CockroachDB Cloud Console.

  • Replace the value for host with the name of the CockroachDB Serverless host (e.g., host: 'free-tier.gcp-us-central1.cockroachlabs.cloud').

  • Replace the value for port with the port to your cluster.

  • Replace the value for username with the user you created earlier.

  • Replace the value for password with the password you created for your user.

  • Replace the value for database with the database that you created earlier, suffixed with the name of the cluster (e.g., database: '{cluster_name}.bank').

  • Remove the ssl: true key-value pair.

  • Remove the extra object and its contents.

  • Uncomment the ssl object with the ca key-value pair, and edit the fs.readFileSync('certs/cc-ca.crt').toString() call to use the path to the cc-ca.crt file that you downloaded from the CockroachDB Cloud Console.

Step 5. Run the code

Open a terminal window, and install the Node.js pg driver:

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$ npm install pg --save

Navigate to the top directory of the application project (e.g., hello-world-typescript-typeorm), and initialize the project:

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$ npm i

Start the application:

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$ npm start

You should see the following output in your terminal:

Inserting a new account into the database...
Saved a new account.
Printing balances from account 1.
Account { id: 1, balance: 1000 }
Inserting a new account into the database...
Saved a new account.
Printing balances from account 2.
Account { id: 2, balance: 250 }
Transferring 500 from account 1 to account 2.
Transfer complete.
Printing balances from account 1.
Account { id: 1, balance: 500 }
Printing balances from account 2.
Account { id: 2, balance: 750 }

What's next?

Read more about using the TypeORM.

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