Change the prompt in clickhouse-client

This article explains how to change the prompt in your Clickhouse client and clickhouse-local terminal window from :) to a prefix followed by :)

If you don’t like how clickhouse client and clickhouse-local display the prompt in your terminal window, it is possible to change it to add a prefix. This article explains how to change the prompt to whatever you want.

The default prompt is your local computer name followed by :) :

The following are variables that you can use in a prompt: {user}, {host}

There are several ways to update the prompt and we’ll go through them each.

—prompt flag

The first way to change the flag is using the --prompt:

clickhouse --prompt 👉

This will add the finger emoji before the smiley face:

Config file - top level

Alternatively, you can provide a prompt prefix in a config.xml file:

<config>
    <prompt>👉 </prompt>
</config>

clickhouse

We can use a config file with any name we like and pass it in using the -C flag:

<config>
    <prompt>🎄 </prompt>
</config>

clickhouse -C christmas.xml

Prefer your config files to be in YAML? That works too:

prompt: 🟡

clickhouse -C christmas.yaml

Config file - connections_credentials

Alternatively, you can specify a prompt per connection credentials. This only makes sense when using clickhouse-client.

<config>
    <connections_credentials>
        <connection>
            <n>prod<n>
            <hostname>127.0.0.1</hostname>
            <port>9000</port>
            <secure>0</secure>
            <user>default</user>
            <prompt>\e[31m[PRODUCTION]\e[0m {user}@prod</prompt>
        </connection>
        <connection>
            <n>dev<n>
            <hostname>127.0.0.1</hostname>
            <port>9000</port>
            <secure>0</secure>
            <user>default</user>
            <prompt>\e[32m[DEVELOPMENT]\e[0m {user}@dev</prompt>
        </connection>
    </connections_credentials>
</config>

We can then try to connect with the dev connection:

clickhouse client -C connections.xml --connection dev

Or the prod one:

clickhouse client -C connections.xml --connection prod

And here’s a YAML version:

connections_credentials:
  connection:
    - name: prod
      hostname: 127.0.0.1
      port: 9000
      secure: 0
      user: default
      prompt: "\e[35m[PRODUCTION]\e[0m {user}@{host}"
    - name: dev
      hostname: 127.0.0.1
      port: 9000
      secure: 0
      user: default
      prompt: "\e[34m[DEVELOPMENT]\e[0m {user}@{host}"

With the dev connnection:

clickhouse client -C connections.yaml --connection dev

And now prod:

clickhouse client -C connections.yaml --connection prod