> ## Documentation Index
> Fetch the complete documentation index at: https://cockroachlabs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Build a TypeScript App with CockroachDB and TypeORM

export const InternalLink = ({version, path = "", children, ...props}) => {
  let detectedVersion = version || "stable";
  if (typeof window !== 'undefined' && !version) {
    const match = window.location.pathname.match(/\/docs\/([^/]+)/);
    if (match) {
      detectedVersion = match[1];
    }
  }
  const normalizedPath = path.startsWith("/") ? path.slice(1) : path;
  return <a href={`/docs/${detectedVersion}/${normalizedPath}`} {...props}>
      {children}
    </a>;
};

export const InternalLink = ({version, path = "", children, ...props}) => {
  let detectedVersion = version || "stable";
  if (typeof window !== 'undefined' && !version) {
    const match = window.location.pathname.match(/\/docs\/([^/]+)/);
    if (match) {
      detectedVersion = match[1];
    }
  }
  const normalizedPath = path.startsWith("/") ? path.slice(1) : path;
  return <a href={`/docs/${detectedVersion}/${normalizedPath}`} {...props}>
      {children}
    </a>;
};

This tutorial shows you how run a simple application built with [TypeORM](https://typeorm.io/#/).

## Step 1. Start CockroachDB

<Tabs>
  <Tab title="Use CockroachDB Cloud">
    ### Choose your installation method

    You can create a CockroachDB Basic cluster using either the CockroachDB Cloud Console, a web-based graphical user interface (GUI) tool, or `ccloud`, a command-line interface (CLI) tool.

    <Tabs>
      <Tab title="Cloud Console (GUI)">
        ### Create a free cluster

        <Note>
          Organizations without billing information on file can only create one CockroachDB Basic cluster.
        </Note>

        1. If you haven't already, [sign up for a CockroachDB Cloud account](https://cockroachlabs.cloud/signup?referralId=docs_typescript).
        2. [Log in](https://cockroachlabs.cloud/) to your CockroachDB Cloud account.
        3. On the **Clusters** page, click **Create cluster**.
        4. On the **Select a plan** page, select **Basic**.
        5. On the **Cloud & Regions** page, select a cloud provider (GCP or AWS) in the **Cloud provider** section.
        6. In the **Regions** section, select a region for the cluster. Refer to <InternalLink version="cockroachcloud" path="regions">CockroachDB Cloud Regions</InternalLink> for the regions where CockroachDB Basic clusters can be deployed. To create a multi-region cluster, click **Add region** and select additional regions.
        7. Click **Next: Capacity**.
        8. On the **Capacity** page, select **Start for free**. Click **Next: Finalize**.
        9. On the **Finalize** page, click **Create cluster**.

           Your cluster will be created in a few seconds and the **Create SQL user** dialog will display.

        ### Create a SQL user

        The **Create SQL user** dialog allows you to create a new SQL user and password.

        1. Enter a username in the **SQL user** field or use the one provided by default.
        2. Click **Generate & save password**.
        3. Copy the generated password and save it in a secure location.
        4. Click **Next**.

           Currently, all new SQL users are created with admin privileges. For more information and to change the default settings, see <InternalLink version="cockroachcloud" path="managing-access#manage-sql-users-on-a-cluster">Manage SQL users on a cluster</InternalLink>.

        ### Get the connection string

        The **Connect to cluster** dialog shows information about how to connect to your cluster.

        1. Select **General connection string** from the **Select option** dropdown.
        2. Open the **General connection string** section, then copy the connection string provided and save it in a secure location.

           The sample application used in this tutorial uses system CA certificates for server certificate verification, so you can skip the **Download CA Cert** instructions.

        <Note>
          The connection string is pre-populated with your username, password, cluster name, and other details. Your password, in particular, will be provided *only once*. Save it in a secure place (Cockroach Labs recommends a password manager) to connect to your cluster in the future. If you forget your password, you can reset it by going to the **SQL Users** page for the cluster, found at `https://cockroachlabs.cloud/cluster/<CLUSTER ID>/users`.
        </Note>
      </Tab>

      <Tab title="ccloud CLI">
        Follow these steps to create a CockroachDB Basic cluster using the `ccloud` CLI tool.

        <Note>
          The `ccloud` CLI tool is in Preview.
        </Note>

        ### Install `ccloud`

        <Tabs>
          <Tab title="Mac">
            You can install `ccloud` using either Homebrew or by downloading the binary.

            #### Use Homebrew

            1. [Install Homebrew](http://brew.sh/).
            2. Install using the `ccloud` tap:

               ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
               brew install cockroachdb/tap/ccloud
               ```

            #### Download the binary

            In a terminal, enter the following command to download and extract the `ccloud` binary and add it to your `PATH`:

            ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
            curl https://binaries.cockroachdb.com/ccloud/ccloud_darwin-amd64_.tar.gz | tar -xJ && cp -i ccloud /usr/local/bin/
            ```

            Use the ARM 64 binary if you have an M-series Mac:

            ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
            curl https://binaries.cockroachdb.com/ccloud/ccloud_darwin-arm64_.tar.gz | tar -xJ && cp -i ccloud /usr/local/bin/
            ```
          </Tab>

          <Tab title="Linux">
            In a terminal, enter the following command to download and extract the `ccloud` binary and add it to your `PATH`:

            ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
            curl https://binaries.cockroachdb.com/ccloud/ccloud_linux-amd64_.tar.gz | tar -xz && cp -i ccloud /usr/local/bin/
            ```
          </Tab>

          <Tab title="Windows">
            In a PowerShell window, enter the following command to download and extract the `ccloud` binary and add it to your `PATH`:

            ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
            $ErrorActionPreference = "Stop"; [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $ProgressPreference = 'SilentlyContinue'; $null = New-Item -Type Directory -Force $env:appdata/ccloud; Invoke-WebRequest -Uri https://binaries.cockroachdb.com/ccloud/ccloud_windows-amd64_.zip -OutFile ccloud.zip; Expand-Archive -Force -Path ccloud.zip; Copy-Item -Force ccloud/ccloud.exe -Destination $env:appdata/ccloud; $Env:PATH += ";$env:appdata/ccloud"; # We recommend adding ";$env:appdata/ccloud" to the Path variable for your system environment. See https://docs.microsoft.com/powershell/module/microsoft.powershell.core/about/about_environment_variables#saving-changes-to-environment-variables for more information.
            ```
          </Tab>
        </Tabs>

        ### Run `ccloud quickstart` to create a new cluster, create a SQL user, and retrieve the connection string.

        The easiest way of getting started with CockroachDB Cloud is to use `ccloud quickstart`. The `ccloud quickstart` command guides you through logging in to CockroachDB Cloud, creating a new CockroachDB Basic cluster, and connecting to the new cluster. Run `ccloud quickstart` and follow the instructions:

        ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
        ccloud quickstart
        ```

        The `ccloud quickstart` command will open a browser window to log you in to CockroachDB Cloud. If you are new to CockroachDB Cloud, you can register using one of the single sign-on (SSO) options, or create a new account using an email address.

        The `ccloud quickstart` command will prompt you for the cluster name, cloud provider, and cloud provider region, then ask if you want to connect to the cluster. Each prompt has default values that you can select, or change if you want a different option.

        Select **General connection string**, then copy the connection string displayed and save it in a secure location. The connection string is the line starting `postgresql://`.

        ```
        ? How would you like to connect? General connection string
        Retrieving cluster info: succeeded
         Downloading cluster cert to /Users/maxroach/.postgresql/root.crt: succeeded
        postgresql://maxroach:ThisIsNotAGoodPassword@blue-dog-147.6wr.cockroachlabs.cloud:26257/defaultdb?sslmode=verify-full&sslrootcert=%2FUsers%2Fmaxroach%2F.postgresql%2Froot.crt
        ```
      </Tab>
    </Tabs>
  </Tab>

  <Tab title="Use a Local Cluster">
    1. If you haven't already, <InternalLink path="install-cockroachdb">download the CockroachDB binary</InternalLink>.
    2. Run the <InternalLink path="cockroach-start-single-node">`cockroach start-single-node`</InternalLink> command:

       ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
       $ cockroach start-single-node --advertise-addr 'localhost' --insecure
       ```

       This starts an insecure, single-node cluster.
    3. Take note of the following connection information in the SQL shell welcome text:

       ```
       CockroachDB node starting at 2021-08-30 17:25:30.06524 +0000 UTC (took 4.3s)
       build:               CCL v21.1.6 @ 2021/07/20 15:33:43 (go1.15.11)
       webui:               http://localhost:8080
       sql:                 postgresql://root@localhost:26257?sslmode=disable
       ```

       You'll use the `sql` connection string to connect to the cluster later in this tutorial.

    <Danger>
      The `--insecure` flag used in this tutorial is intended for non-production testing only. To run CockroachDB in production, use a secure cluster instead.
    </Danger>
  </Tab>
</Tabs>

## Step 2. Get the code

1. Clone [the code's GitHub repository](https://github.com/cockroachlabs/example-app-typescript-typeorm):

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ git clone git@github.com:cockroachlabs/example-app-typescript-typeorm.git
   ```
2. Navigate to the repo directory and install the application dependencies:

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ cd example-app-typescript-typeorm
   ```

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ npm install
   ```

## Step 3. Configure your CockroachDB connection

1. Set the `DATABASE_URL` environment variable to a CockroachDB connection string compatible with TypeORM.

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   export DATABASE_URL="<connection-string"
   ```

   TypeORM accepts the following format for CockroachDB Standard connection strings:

   ```text theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   postgresql://<username:<password@<host:<port/<database
   ```

2. If you haven't already, <InternalLink path="install-cockroachdb">download the CockroachDB binary</InternalLink>.

3. Run the <InternalLink path="cockroach-start-single-node">`cockroach start-single-node`</InternalLink> command:

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ cockroach start-single-node --advertise-addr 'localhost' --insecure
   ```

   This starts an insecure, single-node cluster.

4. Take note of the following connection information in the SQL shell welcome text:

   ```text theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   CockroachDB node starting at 2021-08-30 17:25:30.06524 +0000 UTC (took 4.3s)
   build:               CCL v21.1.6 @ 2021/07/20 15:33:43 (go1.15.11)
   webui:               http://localhost:8080
   sql:                 postgresql://root@localhost:26257?sslmode=disable
   ```

   You'll use the `sql` connection string to connect to the cluster later in this tutorial.

<Danger>
  The `--insecure` flag used in this tutorial is intended for non-production testing only. To run CockroachDB in production, use a secure cluster instead.
</Danger>

## Step 2. Get the code

1. Clone [the code's GitHub repository](https://github.com/cockroachlabs/example-app-typescript-typeorm):

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ git clone git@github.com:cockroachlabs/example-app-typescript-typeorm.git
   ```
2. Navigate to the repo directory and install the application dependencies:

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ cd example-app-typescript-typeorm
   ```

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   $ npm install
   ```

## Step 3. Configure your CockroachDB connection

1. Open the `datasource.ts` file, and comment out the `ssl: true`, `extra` and `options` configuration properties.
2. In the `datasource.ts` file, uncomment `ssl: { rejectUnauthorized: false }`.

<Danger>
  Only use `ssl: { rejectUnauthorized: false }` in development, for insecure connections.
</Danger>

The `DataSource` configuration should look similar to the following:

```ts theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
export const AppDataSource = new DataSource({
    type: "cockroachdb",
    url: process.env.DATABASE_URL,
    ssl: { rejectUnauthorized: false }, // For insecure connections only
    synchronize: true,
    logging: false,
    entities: ["src/entity/**/*.ts"],
    migrations: ["src/migration/**/*.ts"],
    subscribers: ["src/subscriber/**/*.ts"],
})
```

3. Set the `DATABASE_URL` environment variable to the connection string provided in the `cockroach` welcome text:

   ```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   export DATABASE_URL="postgresql://root@localhost:26257/defaultdb?sslmode=disable"
   ```

## Step 4. Run the code

Start the application:

```shell theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
$ npm start
```

You should see the following output in your terminal:

```text theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
Inserting a new account into the database...
Saved a new account.
Printing balances from account 1db0f34a-55e8-42e7-adf1-49e76010b763.
[
  Account { id: '1db0f34a-55e8-42e7-adf1-49e76010b763', balance: 1000 }
]
Inserting a new account into the database...
Saved a new account.
Printing balances from account 4e26653a-3821-48c8-a481-47eb73b3e4cc.
[
  Account { id: '4e26653a-3821-48c8-a481-47eb73b3e4cc', balance: 250 }
]
Transferring 500 from account 1db0f34a-55e8-42e7-adf1-49e76010b763 to account 4e26653a-3821-48c8-a481-47eb73b3e4cc.
Transfer complete.
Printing balances from account 1db0f34a-55e8-42e7-adf1-49e76010b763.
[
  Account { id: '1db0f34a-55e8-42e7-adf1-49e76010b763', balance: 1000 }
]
Printing balances from account 4e26653a-3821-48c8-a481-47eb73b3e4cc.
[
  Account { id: '4e26653a-3821-48c8-a481-47eb73b3e4cc', balance: 250 }
]
```

## What's next?

Read more about using the [TypeORM](https://typeorm.io/#/).

You might also be interested in the following pages:

* [Client Connection Parameters](connection-parameters)
* [Connection Pooling](connection-pooling)
* [Data Replication](demo-replication-and-rebalancing)
* [Fault Tolerance & Recovery](demo-fault-tolerance-and-recovery)
* [Replication & Rebalancing](demo-replication-and-rebalancing)
* [Cross-Cloud Migration](demo-automatic-cloud-migration)
* [Automated Operations](orchestrate-a-local-cluster-with-kubernetes-insecure)
