DuckDB provides us with plenty of functions for working with lists, including a couple that actually create lists for us.
In particular, the list_value() and list_pack() functions are specifically for creating lists in DuckDB. We’ll run through some examples of these functions below.
If we have a list in DuckDB, and we want to convert it to a string, there are a number of options on the table. Basically, what we want to do is combine/concatenate all elements into a single string. Let’s take a look at five ways to convert a list to a string in DuckDB.
DuckDB’s command-line interface (CLI) provides a simple built-in method for outputting query results as tab-separated values (TSV) using the .mode tabs command.
This article takes a quick look at this output mode and explores some of the options available for when outputting query results as a tab-separated list.
One of the many JSON functions that DuckDB provides is the json() function, which parses and minifies JSON values. We pass the JSON data to the function, and it parses and minifies the JSON, then returns the result.
DuckDB provides us with a couple of ways to get the weekday name from a date or timestamp value. This could be the full day name, such as Monday, or the short/abbreviated day name, such as Mon.
Here are two ways to return the day name from a date in DuckDB.
DuckDB has a json_keys() function that we can use to extract the keys from a JSON object. It returns the keys as a list of strings (LIST of VARCHAR).
Most SQL developers are familiar with the min() function that allows us to get the minimum value from a data set. But if we want to get the minimum value from a list, passing the list to the min() function won’t quite cut it. But don’t despair! Finding the minimum value in a list is just as easy. Here are three ways to do it. And yes, we can even use the min() function if we want.
If you’ve ever used list_concat() or any of its aliases to concatenate lists in DuckDB, you may have been disappointed to find out that it only concatenates two lists. Any more than two lists and it returns an error. At least that’s how it works at the time of this writing.
Fortunately, there are some alternatives we can use in order to concatenate three or more lists.
Here are four ways to concatenate three or more lists in DuckDB.
DuckDB has emerged as a powerful analytical database system designed for fast in-memory data processing. One common analytical task involves calculating time differences between events—whether measuring intervals between transactions, tracking service response times, or analyzing temporal patterns in time series data.
This article provides an exploration of calculating time differences in DuckDB, covering both basic and slightly more advanced techniques.
DuckDB provides us with a couple of easy ways to perform additions and subtractions on dates. In particular, we can use the - operator to do the job, or the date_add() operator combined with the - operator.
Here are two options for subtracting days from a date in DuckDB.