Using the .nullvalue Command to See NULL Output in the DuckDB CLI

By default, when a query returns a null value in the DuckDB command line interface (CLI), an empty string is displayed. This may or may not be what you want. But if you’re like me, you probably want DuckDB to explicitly tell you that it’s a null value. After all, if an empty string is returned, perhaps the data contained an empty string?

Fortunately, DuckDB provides us with the .nullvalue dot command so that we can change the output of null values.

Continue reading

Understanding the STRPTIME() Function in DuckDB

DuckDB provides us with a good selection of date/time functions. The strptime() function is a useful one for times where you need to convert a date string into a valid timestamp value; its sole purpose is to parse strings into timestamps.

In this article, we’ll look at how the strptime() function works, along with some examples to demonstrate.

Continue reading

How to Format Dates in DuckDB

When working with SQL databases such as DuckDB, dates usually conform to a specific format. In particular, when we create dates in DuckDB, they must conform to the ISO 8601 format (YYYY-MM-DD). It’s the same with time (hh:mm:ss[.zzzzzz][+-TT[:tt]]) and timestamp values (YYYY-MM-DD hh:mm:ss[.zzzzzzzzz][+-TT[:tt]]).

But what if we have a requirement to present these dates or timestamps in a different format?

Fortunately, DuckDB provides us with tools to so. This article explains how to format date and timestamp values according to a specified format.

Continue reading