KSQL Quickstart with Docker - SQL

If you are a programmer looking to learn more about KSQL and how to use it with Docker, you're in the right place! In this quickstart guide, we will walk you through how to get started with KSQL using Docker, and show you some basic SQL commands.

Prerequisites

Before getting started, you will need to have Docker and Docker Compose installed on your machine. You can find instructions on how to install these on the Docker website. Additionally, you'll need a basic understanding of SQL.

Getting Started

To get started with KSQL using Docker, you can follow these steps:

1. Clone the KSQL quickstart repository.

git clone https://github.com/confluentinc/ksql-quickstart

2. Go into the cloned directory.

cd ksql-quickstart

3. Start the Docker containers.

docker-compose up -d

4. Open a KSQL CLI session.

docker-compose exec ksql-cli ksql http://ksql-server:8088

Creating a Stream

Now that you have a KSQL CLI session open, you can create your first stream. In this example, we'll create a stream called "pageviews" that will capture data from an input topic called "pageviews":

CREATE STREAM pageviews (viewtime BIGINT, userid VARCHAR, pageid VARCHAR) \
WITH (kafka_topic='pageviews', value_format='JSON');

Querying Stream Data

Now that we have a stream created, we can query it to see what data is being captured. The following query will show us the first 10 records in the "pageviews" stream:

SELECT * FROM pageviews LIMIT 10;

Final Thoughts

Congratulations, you now know how to get started with KSQL using Docker and create a stream with SQL commands! Of course, this is just the tip of the KSQL iceberg, and there's much more you can do with KSQL. We encourage you to explore the KSQL documentation and try out some more complex queries to see what you can do with this powerful tool.