--- layout: page title: How-to Guides tagline: Frequently used ksqlDB patterns description: Quick lessons that help you work with common ksqlDB functionality. keywords: pattern, satructured data, changelog, connector, query, function, identifier, timestamp, variable --- Follow compact lessons that help you work with common ksqlDB functionality.
Query structured data

Process and query structured data types like structs, maps, and arrays.

Learn →
Convert a changelog to a table

Create a table representing the latest values in a stream.

Learn →
Use connector management

Source and sink data from external systems.

Learn →
Update a running persistent query

Change a running persistent query with no downtime.

Learn →
Create a user-defined function

Extend ksqlDB and invoke code that you wrote.

Learn →
Control the case of identifiers

Specify the exact capitalization of object names.

Learn →
Use a custom timestamp column

Perform time-based operations using a timestamp in each record.

Learn →
Test an application

Build test suites to assert correct program behavior.

Learn →
Substitute variables

Change the content of a query based on variables.

Learn →
Transforming columns with structured data

Transform columns of structured data without user-defined functions.

Learn →
Help us write another?

We're always looking for more guides. Just send a pull request!

Contribute →