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 CockroachCloud. The instructions below will adjust accordingly.

Create a free cluster

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

    Note:

    This cluster will be free forever.

  5. (Optional) Select a cloud provider (GCP or AWS) in the Additional configuration section.

  6. (Optional) Select a region in the Additional configuration section. For optimal performance, select the cloud provider region closest to the region in which you are running your application.

  7. 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://<user>@<free-tier-host>.<region>.cockroachlabs.cloud:26257/defaultdb?sslmode=verify-full&sslrootcert='$HOME'/.postgresql/root.crt&options=--cluster=<cluster-name>-<tenant-id>'
    

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    cockroach sql --url 'postgresql://<user>@<free-tier-host>.<region>.cockroachlabs.cloud:26257/defaultdb?sslmode=verify-full&sslrootcert='$HOME'/.postgresql/root.crt&options=--cluster=<cluster-name>-<tenant-id>'
    
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    cockroach sql --url "postgresql://<user>@<free-tier-host>.<region>.cockroachlabs.cloud:26257/defaultdb?sslmode=verify-full&sslrootcert=$env:appdata/.postgresql/root.crt&options=--cluster=<cluster-name>-<tenant-id>"
    

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

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    $ cockroach demo \
    --empty
    

    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.

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

    # Connection parameters:
    #   (console) http://127.0.0.1:61009
    #   (sql)     postgres://root:admin@?host=%2Fvar%2Ffolders%2Fk1%2Fr048yqpd7_9337rgxm9vb_gw0000gn%2FT%2Fdemo255013852&port=26257
    #   (sql/tcp) postgres://root:admin@127.0.0.1:61011?sslmode=require    
    

    In this example, the port number is 61011. You will use the port number in your application code later.

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 CockroachCloud 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 CockroachCloud 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;
    

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 CockroachCloud Console.

  • Replace the value for host with the name of the CockroachCloud Free 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 CockroachCloud 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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